PHOTO-ENGRAVING, 
 
A, OampbblIi, 
 
 PA8SA30, N. J. 
 
 J. A. OAM.rBEIil'* 
 
« 
 
CD 
 
 J, A. CambbslIi, 
 
PHOTO-ENGRAVING. 
 
 A PRACTICAL TREATISE 
 
 ON THE PRODUCTION OF PRINTING BLOCKS BY 
 MODERN PHOTOGRAPHIC METHODS. 
 
 BY 
 
 CARL SCHRAUBSTADTER, Jr. 
 
 PUBLISHED BY 
 
 C. SCHRAUBSTADTER, JR., 
 SAINT LOUIS. 
 1892. 
 
COPYRIGHT, 1892, 
 
 BY 
 
 CARL SCHRAUBSTADTER, Jr. 
 
 PRESS OF 
 B. WOODWARD CO., ST. LOUIS. 
 
CONTENTS. 
 
 Page. 
 
 Chapter I. 
 
 Historical Sketch 7 
 
 Chapter 11. 
 
 Arrangement and Equipment of the Shop 13 
 
 Chapter 111. 
 
 Preparation of Chemicals 25 
 
 Chapter IV. 
 
 Manipulation . 33 
 
 Chapter V. 
 
 Defective Negatives and their Causes 41 
 
 Chapter VI. 
 
 The Print on Zinc 47 
 
 Chapter Vll. 
 
 Powdering and Etching 61 
 
 Chapter VIII. 
 
 Gumming up - 69 
 
 Chapter IX. 
 
 Routing and Finishing 73 
 
 Chapter X. 
 
 Printing with Asphaltum 85 
 
 Chapter XI. 
 
 Half Tone 88 
 
 Chapter XII. 
 
 Miscellaneous Hints , 94 
 
 Chapter XIII." 
 Double Washout Gelatine Engraving loi 
 
 Chapter XIV. 
 
 Single Washout Methods 1 19 
 
 Chapter XV. 
 
 Swelled Gelatine Engraving 122 
 
4 
 
INTRODUCTION. 
 
 The many requests that I recommend some good manual 
 on this subject led to my reading ail obtainable. Aside from 
 the fact that the best were written in foreign languages, none 
 were found which I considered entirely satisfactory. Not that 
 they were without great value, but none were up to date; some 
 attempted concealments, some gave no information on points 
 necessary to a clear understanding of the subject, and in others 
 the arrangement was inconsequent, or the work the result not 
 of actual practice but of experiments only. Yet, in my opinion, 
 the most frequent fault was their undue length, the desire of 
 the writers being apparently to show all the variations of the 
 different methods of accomplishing the same end. As many of 
 these had, even at the time of writing, been superseded, and 
 others are now but seldom used, I thought it best to write a 
 clear description of those methods only which have been sanc- 
 tioned by usage in commercial establishments. Methods for 
 which others slightly better might sometimes have been sub- 
 stituted, but which on account of economy, speed and general 
 utility, have been widely adopted. In the belief that too much 
 general information would tend to confuse the beginner, and 
 that many different recipes would result in his trying all with- 
 out becoming acquainted with the possibilities of any, I may 
 have erred in the direction of undue brevity, or appear dog- 
 matic. 1 will thank the reader to point out any errors 1 
 have committed. I have also omitted, as much as pos- 
 sible, all theoretical knowledge; not that I consider theory 
 
6 
 
 INTRO D UCTION. 
 
 unessential, but it is facts which the beginner needs — a little 
 knowledge being often a dangerous thing. After a practical 
 acquaintance with the work, a thorough study of optics, chem- 
 istry and photography alone will enable the operator to obtain 
 the best work and experiment intelligently. In a chapter 
 devoted to this subject I have endeavored to concisely catalogue 
 the difficulties experienced by beginners, together with the 
 proper remedies. 
 
 Neither is this work offered as a substitute for experience. 
 The utmost which can be accomplished by a text book is to 
 prevent the experimenter from wasting his time and energy in 
 fruitless places. Wherever possible, personal instruction by 
 a practical man is recommended. Learning from a book alone 
 is often the most expensive method. 
 
 Among the many friends to whom I am indebted for aid 
 and advice in preparing this book are Messrs. Chas. Chetham, 
 G. H. Frommann and Lon Sanders. 
 
 C. S., Jr. 
 
CHAPTER I. 
 
 Historical Sketch. 
 
 FROM its beginning the art of printing has been quici< to 
 avail itself of all advances in science and art. Often,, 
 indeed, experiments were conducted to a successful issue' 
 long before the conditions were such as warranted the introduc- 
 tion of the results from a commercial standpoint. This is par- 
 ticularly true of photo-engraving. In the strict sense of the' 
 word, photography is a printing process, but the general under- 
 standing of printing is a production of copies by means of ink: 
 and pressure. The various methods and processes are so 
 closely connected, and in so many ways run into each other,, 
 that an exact nomenclature is almost impossible. To add to. 
 the difficulty, the experiments in photo-engraving, conducted! 
 over such a long period, and by so many experimenters in dif- 
 ferent parts of the globe, have resulted in a confusion of terms, 
 which can only be simplified by time and usage. Aside from, 
 pure photography, in which the duplication is accomplished by- 
 sensitizing a suitable material and exposing it to the action of 
 light beneath a negative, photography has been applied to all! 
 existing forms of printing, to a greater or less extent resembling, 
 the simpler printing methods. Thus we have Artotypy, Photo- 
 lithography, Woodburytype, Photo-gravure, and other methods 
 of producing intaglio engravings, corresponding closely to the 
 copper plate method. All these, however, are of little use to 
 the practical printer, as the engravings cannot be printed in 
 a type form. Only of late years have the conditions been 
 such as would admit of the production of relief engravings, 
 by the aid of photography. 
 
 As before noted, confusion of nomenclature makes it diffi- 
 cult to give good definitions. Photo-relief engraving perhaps 
 expresses the idea better than any other term, but, aside from 
 its awkwardness and length, confining it to its strict sense 
 necessarily excludes such methods as do not directly avail 
 
 / 
 
8 
 
 HISTORICAL SKETCH. 
 
 themselves of the action of light, and as the modern processes 
 are to a great extent the results of experiments in this direction, 
 and the operator is called upon to use them, the term must be 
 set aside. Chemigraphy, a word proposed by a number of 
 'German authors, and to a certain extent adopted on the con- 
 tinent, presents the objection that, among others, lithography 
 is also a chemical process. Amongst the English-speaking 
 artists the word "Process" has been largely adopted to distin- 
 guish all photographic methods from wood engraving. This 
 term has taken some root amongst the English printers, but as 
 photo-engraving can hardly be said to be more of a "process" 
 than wax engraving, it is hardly applicable. The term gene- 
 rally sanctioned by usage is "Photo-engraving." Though by 
 some extended so as to cover all methods of photo-reproduction, 
 and by others used to distinguish the gelatine processes from zinc 
 etching, it is widely and generally used to include such pro- 
 cesses only as produce relief plates, and it is in this sense that 
 it will be used- throughout this work. Zinc etching is the 
 method of producing a relief printing plate by protecting the 
 surface of the lines, and removing the rest of the metal so as 
 to leave them in relief. Generally the drawing is reproduced 
 on the metallic plate by means of photography, and this method 
 has been called photo-zinc etching or photo-zinc engraving, in 
 distinction from that process in which the drawing is made by 
 the artist directly upon the surface of the metal. Copper and 
 other metals are sometimes substituted for the zinc, but it is 
 rarely spoken of as copper etching, the term zinc etching being 
 generally used to include these variations. The acid resisting 
 coating is sometimes made by covering the metal with a thin 
 sheet of asphaltum and exposing it beneath a negative, the 
 parts reached by the light being rendered insoluble in turpen- 
 tine, and remaining on development. Usually the surface is 
 ■sensitized by albumen, or other organic matter, in combination 
 with bichromate of potash or ammonia, the process being based 
 on the insolubility of such substances in cold water after ex- 
 posure to the light. This property is also made use of in the 
 photo-gelatine washout method, usually referred to simply as 
 the washout process, in which a sheet of gelatine sensitized 
 with one of these chrome salts is exposed beneath a suitable 
 iiegative. The soluble portions are afterwards washed away, 
 
HISTORICAL SKETCH. 
 
 9 
 
 giving a relief plate. Another property of bicliromatized gela- 
 tine is the loss of its tendency to swell by absorbing water after 
 exposure to light. In the gelatine swell method this is taken 
 advantage of, the lines being hardened by the action of light, 
 and the surrounding spaces afterwards brought into relief by 
 soaking in water. Plaster casts, and afterwards a metal cast,, 
 produce a relief plate suitable for the press. The term half- 
 tone, as applied to relief engravings of a certain class, is hardly 
 satisfactory, but its universal adoption will not permit the sub- 
 stitution of another word. This is a photographic method by 
 which a printing plate is produced in relief from a photograph or, 
 painting in which there are no lines or dots, but simply a grada- 
 tion of tints. There are a number of ways of producing the 
 lines or dots necessary in such engravings, but almost univer- 
 sally they are made by intervention of a screen plate between 
 the copy and the sensitized plate. From the line or stipple 
 negative, a drawing or relief block may be made by any of the 
 above methods, although zinc etching. is generally selected. 
 
 It is a curious fact that Niepce, the originator of photography 
 and the co-worker of Daguerre, made his first experiments with 
 asphaltum, a substance which is to-day used for obtaining the 
 fmest photo-engravings, and that the object of these experi- 
 ments was the production of a printing plate, hi 1824 he made 
 a picture in a camera obscura, in which the image was produced 
 on a silver plate coated with asphalt. Shortly afterwards he 
 is said to have etched some of these plates in relief. In recent 
 times. Dr. Kaysar has promulgated the present method of in- 
 creasing the sensitiveness of the asphaltum. A process of 
 etching daguerreotypes so as to produce printing plates was set 
 forth by Grove in 1841, and shortly after, Berra attempted to 
 produce printing plates by a similar method. These plates, how- 
 ever, were too shallow to be of much value. Probably the first 
 practical use of such engravings was for illustrating "Le 
 Journel Amusant" in Paris. In 1847 Niepce de St. Victor, 
 nephew of Daguerre's partner, succeeded in sensitizing an albu- 
 men film on glass. During the 50's numerous experiments 
 were made throughout Europe. In 185 1 collodion, suggested 
 by Legray, was practically applied by Archer. In 1852 Fox 
 Talbot, whose discoveries in photography were made public 
 even before those of Niepce and Daguerre, obtained a patent 
 
1.0 
 
 HISTORICAL SKETCH. 
 
 for a process in which steel plates were coated with bichromate 
 of potash and gelatine. After exposure beneath a negative the 
 soluble gelatine was washed off and the plate etched into relief 
 by bichloride of platinum. It will be seen thatthis method closely 
 resembles modern zinc etching, hi 1859 Poitevin at Paris, and 
 Pretch in Vienna, applied for patents based on the fact that 
 gelatine treated with certain chrome salts, after exposure 
 to the light, loses its property of absorbing water and swelling. 
 They experimented with a method similar to the gelatine swell 
 process of to-day. Pretch obtained a patent in that year and 
 Poitevin, in 1855, and about the same time Pretch also succeeded 
 in producing a grained plate, obtaining very fair results. Shortly 
 afterwards Fox Talbot made use of the other properties of bi- 
 chromatized gelatine, namely its impermeability and its insolu- 
 bility in water after exposure to light. Thomas Sutton and 
 John Pouncy also experimented in 1858. In 1859 Osborne in 
 Australia, and Asser in Holland, simultaneously introduced the 
 method of photograpliing on transfer paper, developing the 
 image with fatty ink and transferring this image to stone. Sir 
 Henry James soon after transferred to zinc. In 1859 a patent 
 was taken out in Austria for photo-lithography, the print being 
 made directly on the stone by asphalt and developed with tur- 
 pentine. Amongst others, Falk, Schippang, Lea, Kronheim, 
 Fontaine, Placet, Swan and Vogel afterwards contributed to- 
 wards the perfection of the different methods. While some 
 good results were obtained, commercial success had been 
 achieved by none, and it was not until the Austrian Govern- 
 ment commenced its series of experiments that modern photo- 
 engraving became a permanent success. At first these ex- 
 periments were conducted by Pretch, who on account of his 
 age and failing faculties did not even succeed in duplicating 
 his former achievements. In 1873 Prof. Husnik took his place 
 and succeeded in producing practical printing plates. At this 
 time experimenters throughout the civilized world were begin- 
 ning to take renewed interest in photo-engraving. The gela- 
 tine swell process was perfected so that fair results were ob- 
 tainable, and photo-lithography was also brought to a practical 
 basis. Long before this experiments had been made with a 
 view to producing a relief printing plate by means of etching. 
 In 1789 and afterwards, the talented and eccentric artist, Wm. 
 
HISTORICAL SKETCH. 
 
 11 
 
 Blake, illustrated "The Book of Thel" and "The Songs of In- 
 nocence" by drawing his designs on copper with acid-resisting 
 ink and etching out the white spaces with aquafortis. Blake 
 claimed that the method and the ink were revealed to him by 
 his deceased brother's spirit. Senefelder's first experiments 
 were with the idea of producing a relief plate by drawing on 
 the surface of a stone with an acid-resisting ink and etching 
 out the white spaces. Had he been successful it is possible 
 that lithography of to-day would still be unknown. A number 
 of experimenters paved the way for the present zinc etching 
 method. During the 60' s a process was attempted in which 
 the metal was covered with an etching ground. On this the 
 design was scratched. The plate was then subjected to the 
 action of acid, producing a sunken engraving. After cleaning, 
 the lines were filled with solder or with a mixture of asphaltum 
 and ink, as for printing a copper plate, and the plate again 
 etched, bringing the lines into relief. There were many varie- 
 ties of this process. In one of them the scratched plate was 
 hung in the battery, and gold or other acid-resisting metal de- 
 posited on the lines, so that the etching could be made. After 
 the first etch, acid-resisting ink was applied to the plate and 
 rubbed off with a circular motion so that enough was left to 
 protect the sides of the lines during the subsequent etch. The 
 results, however, were hardly satisfactory. The first success- 
 ful application of photography to zinc etching was by the use 
 of transfer paper, an offshoot of photo-lithography. A sheet of 
 paper coated with bichromatized gelatine was exposed beneath 
 a negative and inked with a lithographic roller. On rubbing 
 it while beneath water, the ink was removed from all such por- 
 tions as had not been exposed to the light. The transfer to 
 the polished zinc plate was then made in an ordinary lithogra- 
 phic press. 
 
 The next step of improvement was the direct printing on 
 zinc. Although the asphalt method was one of the earliest in 
 use for etching, and Talbot had used bichromatized gelatine on 
 steel, it was not until the bichromatized albumen solution with 
 a coating of ink was adopted that the product became a com- 
 mercial article. The greatest difficulty was experienced in pro- 
 tecting the sides of the lines so that a good relief could be ob- 
 tained without losing the more delicate lines of the drawing. 
 
12 
 
 HISTORICAL SKETCH. 
 
 Numerous methods were proposed, and a number put to prac- 
 tical use. The experimenters may be counted not only by 
 hundreds but by thousands, and as many endeavored to keep 
 their methods secret, the amount of credit due to each is hard 
 to determine. Even now it is difficult to obtain access to the 
 best establishments, and almost every engraver has his own 
 methods and recipes, but the change. of workmen from one 
 situation to another, and the tendency, every year more ap- 
 parent, to formulize facts and abolish mystery have tended to 
 eliminate the less practical methods, so that the processes em- 
 ployed by the various photo-engravers do not essentially differ. 
 To trace the development of the art would involve not only a 
 history of photography, but of lithography and wood and copper 
 engraving as well. The scope of this work will not permit 
 even an attempt in this direction. 
 
 Probably the first zinc etching in America was done by 
 Chas. Henry, a Frenchman, who came to this country in 1865 
 and formed a partnership with a wood engraver named Arnold. 
 The method used was that of making a photographic print on 
 lithographic transfer paper, transferring it to the surface of a 
 plate and etching it with sulphuric acid. The results were not 
 altogether satisfactory, and the partnership was soon dissolved, 
 Henry afterwards entering into the employ of Frank Leslie. 
 Renewed interest in the process, and the gradual solution of 
 difficulties which (though apparently small and unimportant to 
 one unfamiliar with engraving) stood in the way of success, 
 induced many practical men to engage in the business. A 
 glance at the trades' papers of the last decade will show the ex- 
 traordinary progress of the art, both as to the number of firms 
 engaged in the business and the quality of the work. 
 
CHAPTER II. 
 
 ARRANGEMENT AND EQUIPMENT OF THE SHOP. 
 
 Unless erected expressly for the purpose, a good workshop 
 is difficult to find. With slight alteration, an old photographic 
 studio will answer very well. As these are seldom located in 
 the right district, a light room, preferably at the top of a build- 
 ing, with the ceilings and windows as high as possible, is to be 
 chosen. A skylight, though expensive, is a most profitable 
 investment. Where circumstances warrant the necessary out- 
 lay, an arc electric lamp will render the operator independent 
 of daylight. Whenever practicable, a separate room should be 
 used for^'each department, such as photographing, etching and 
 finishing. It is absolutely necessary that the dark room should 
 be kept separate from the other working space, and, if possible, 
 also the etching and photographing. On the next page (Fig. i ) are 
 plans for a shop having all modern conveniences, and adapted to 
 doing a great deal of work economically, hi this arrangement 
 the photographing room is far enough away to keep out all dust, 
 dirt, and disturbances made by the other departments. 
 
 In general, it will be noted that running water is desir- 
 able in most of the rooms, and it is most economical to have 
 the sinks close together. Next to the photographers, the artists 
 and finishers require the best light, and where there is no sky- 
 light for them, the north wall is best, as there is no direct sun- 
 light during any part of the day. As the etchers also require 
 good light, the tubs should be placed close to the windows. In 
 the photographing room, shown at the northwest corner, may 
 be seen two cameras, i, hung on swings, with the electric light, 
 2, between them; 3 represents the reflector; 4, bench for 
 tacking up copy, etc.; while the dotted lines show the outline 
 of the skylight; 5 is the case for chemicals; 6, compounding 
 table; and 7, a sink for intensifying negatives, having a small 
 bench at its side. 
 
14 ARRANGEMENT AND EQUIPMENT 
 
 Above all, select a portion of a building which is solid. The 
 vibration of machinery, and even of passing wagons, will, in 
 some buildings, disturb the camera so that no compensating 
 
 1 
 
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 Fig. I. 
 
 device will make the negatives perfect. The ceiling and walls 
 should be painted or whitewashed light gray, and the floor 
 painted some dark color. The size of room will depend upon 
 the nature of the work and the number of operators. For a 
 
OF THE SHOP. 
 
 15 
 
 14x17 inch camera, a 12-foot slide is not too long, consequently 
 there should be room to place this in a good position. The 
 lighting is of the utmost importance. Wherever possible, a sky- 
 light should be let into the ceiling. This should be a trifle longer 
 than the camera swing, and wide enough to accommodate the 
 
 Fig. 2. 
 
 number of cameras used. Thus, for a gallery running one 
 camera 10 x 12 and one 14 x 17, the skylight should be about 
 10 x 14 feet. Its shape and construction will of course depend 
 upon the building, but the larger the better. If possible, it 
 
16 ARRANGEMENT AND EQUIPMENT 
 
 should slant at an angle of 15 to 30 degrees towards the north, 
 as this will provide against direct sunlight upon the copying 
 board for the greater part of the day. The panes of glass 
 should be large, so that the cross-bars will not cut off the light. 
 They should lap each other as little as possible, an eighth of 
 an inch being sufficient. Use clear, white glass. A slight 
 yellowish tint will perceptibly decrease the actinic power of the 
 light. 
 
 In very few localities can the daylight be depended upon, 
 and therefore all well equipped shops use electric light. This 
 is particularly true of newspaper offices where the work is done 
 entirely after sunset, and the skylight consequently dispensed 
 with. Though requiring somewhat longer exposure, electric 
 light has the advantage of being always exactly the same, thus 
 enabling the photographer to time his exposure much better 
 than with the constantly changing sunlight. Incandescent 
 lamps are not sufficiently intense. The ordinary arc lamp will 
 answer, but, as the upper carbon alone is fed, the position of 
 the arc changes constantly, and for this reason a focusing lamp, 
 in which the carbons are fed towards the center, is preferable, 
 as it will always throw the light in the same direction. Such 
 a lamp is shown in Fi^. 2. A metal reflector eight or ten inches 
 in diameter should be placed back of the arc. The lamp may 
 be hung from the ceiling in the usual manner, or, better still, 
 placed on a light wooden stand about four feet high, so that the 
 direction of the light may be regulated. It will generally be 
 found most economical to purchase from some electric light 
 company, but establishments having their own incandescent 
 plants can make use of the current by purchasing a converter. 
 Running across the skylight should be a beam strong enough 
 to bear the weight of the camera swings. The construction 
 shown in Fig. 3 is preferable. The cross beam should be as 
 srnall as consistent with strength, otherwise the shadow thrown 
 by it may interfere with photographing. A wire rope is pre- 
 ferable, as it will wear longer. The swing should be adjusted 
 so that the operator will not have to assume an inconvenient 
 position. A height which will make the center of the camera 
 come six inches below his chin will be found about right. The 
 slides should be about a quarter of an inch wider than the base 
 of the camera, so as to allow it to move easily. 
 
OF THE SHOP. 
 
 17 
 
 The following table gives the length of bed for ordinary 
 reductions: 
 
 For 8 X 10 inch camera, length of bed, 8 feet. 
 For lo X 12 inch camera, length of bed, 9 feet. 
 For 11x14 inch camera, length of bed, 10 feet. 
 For 14 X 17 inch camera, length of bed, 12 feet. 
 For 17 X 20 inch camera, length of bed, 15 feet. 
 For 20 X 24 inch camera, length of bed, 20 feet. 
 
 I 
 
 Fig. 3- 
 
18 
 
 ARRANGEMENT AND EQUIPMENT 
 
 The purpose of a swing is to guard against vibration, the 
 copy board and camera moving together if disturbed. Most 
 operators prefer to have the end on which the copy board rests 
 
 Fig. 4. 
 
 slightly lower, so that the latter will be kept in position by 
 gravity. As shifting the camera for various reductions changes 
 the center of gravity, a movable weight may be provided 
 for balancing. Generally, the copy-board holder shown in 
 
OF THE SHOP. 
 
 19 
 
 Fig. 3 is provided. This may be fastened permanently to 
 the swing, and the copy pinned directly upon it. Most opera- 
 tors prefer to pin their copy to another board with thumb tacks, 
 and lay this board against the holder, as illustrated in Fig. 4. 
 Where large drawings are to be copied in sections, a holder 
 which will permit the copy-board being slid across the swing 
 without changing the focus is preferable. Where circumstan- 
 ces do not warrant the outlay of a skylight or an electric light, 
 the stand illustrated in Fig. 4 will be found desirable, as it can 
 be moved around to accommodate the shifting light. Many 
 operators who have fixed light prefer a stand to the swing, 
 omitting the springs and substituting small rubber balls for the 
 castors. 
 
 Of the utmost importance is the lens. This should be of 
 the rectilinear type. A portrait lens will not answer. Begin- 
 ners are apt to make the mistake of purchasing a cheap lens. 
 It is far better to purchase a good one having a smaller field, 
 even though an occasional large job has to be made in sections. 
 The average job will be much smaller than 8 x 10 inches, and 
 few are larger than 10 x 12. Used with a large diaphragm, a 
 comparatively small lens will make a large picture, but the cor- 
 ners will not be sufficiently sharp to make a good print. Con- 
 sequently it is stopped down by a small diaphragm. While 
 this increases the sharpness, it diminishes the amount of light 
 admitted, and consequently increases the length of exposure, 
 and is liable to veil the lines. As the wet collodion process is 
 altogether used, and the length of exposure limited to the time 
 the sensitized plate will remain moist, the necessity of a lens 
 which will make a clear picture when stopped with a medium 
 diaphragm is apparent. This is particularly true in summer, 
 when evaporation takes place rapidly. There are many differ- 
 ent makes of lenses. Amongst the best are the Dallmeyer, 
 Steinheil, Voigtlander, Ross and Taylor & Hobson. If possi- 
 ble, purchase a lens from some reliable concern, with the privi- 
 lege of returning unless satisfactory. If you can procure the 
 assistance of an experienced photographer in making the tests, 
 so much the better. If not, hold the lens in the hand and look 
 through the aperture at a piece of paper tinted light blue. If 
 wrongly constructed, it may have "ghosts," which will be 
 visible in the form of mist or fog which appears to be in the 
 
20 
 
 ARRANGEMENT AND EQUIPMENT 
 
 glass. If such is the case, the lens should be rejected. If per- 
 fectly clear, it should be tested for speed, covering power, ac- 
 curacy in copying straight lines, intensity and equal distribution 
 of light. These points may be settled by making a negative, 
 but before rejecting it be sure that the fault is in the lens and 
 not in your chemicals, light, other apparatus, or the lack of 
 photographic knowledge. 
 
 The ordinary copying camera, illustrated in Fig. 5, fitted 
 
 Fig. 5. 
 
 with long bellows and cone, is generally used. 10 x 12 and 11 
 X 14 will be found the most convenient sizes. The lens should 
 be fastened exactly in the center of the lens board, a hole being 
 bored to fit it, and the edges of the wood blackened to corres- 
 pond with the interior of the camera. The ground glass should 
 be without perceptible grain, and when placed in the camera 
 should come in precisely the same position that the sensitized 
 plate will afterwards occupy. To determine this, take out the 
 lens board, and measure the distance between the front of the 
 camera and the glass. It should be exactly the same from each 
 of the four corners. Then remove the ground glass and insert 
 in its place the plate holder containing the largest size glass it 
 will admit. Pull out the slide, and measure as before, when 
 the distance should be exactly the same. The old style plate 
 holders are provided with kits to fit various sizes of glass. They 
 
OF THE SHOP. 
 
 21 
 
 have been almost entirely superseded by the modern Bonanza 
 and Benster holders, which need not be described here. The 
 enlarging and reducing camera shown in Fig. 6 resembles the 
 
 Fig. 6. 
 
 other, and can be used in the same manner, but the lens can 
 also be placed in the interior of the camera, and a transparency 
 in the front. This arrangement is by some preferred for mak- 
 ing half tone negatives, and also for making large silver prints. 
 Though constructed on the same principles, there is a great 
 difference in the quality of the various makes of cameras, and 
 they should always be purchased from some dealer of reputation. 
 
 The operating room should be provided with a table for 
 tacking copy to the board. Near the dark room there should 
 be a sink with running water, and along side of this a bench 
 provided with rubber trays, etc., for intensifying and fixing 
 negatives, as also for cleaning the negative glasses. Beneath 
 the sink should be placed the tub for receiving the used nega- 
 tives. On the outside of one of the windows which has a good 
 light should be placed a stout shelf twelve or fifteen inches 
 wide, on which the printing frames for making silver prints and 
 the extra silver bath may be placed. In establishments hav- 
 ing electric light a table of suitable height may be used for ex- 
 posing the prints on zinc. This will be spoken of at length 
 further on. 
 
 Nothing but the chemicals and apparatus in actual use 
 should be placed in the dark room No. i, which opens from the 
 operating room, and which is intended for making negatives 
 
22 
 
 ARRANGEMENT AND EQUIPMENT 
 
 only. Again referring to Fig. i, 8 represents a window; 9, the 
 sink; 10, bath holders, and 11, shelves. The room should be 
 large enough to work in comfortably. Six by eight feet will do 
 very well, but eight by ten is not too large. Where there are 
 a number of operators it will be best to have a small room for 
 each, as during the occupancy of the room the door must not 
 be opened. In one end there should be a window glazed with 
 orange glass, if the situation is such that direct sunlight enters 
 at any time while the room is being used, an awning or curtain 
 should be provided, if the ceilings and walls are whitewashed, 
 they had best be scraped and painted a light yellow. If of 
 wood, they should be shellaced or varnished. In place of the 
 paint and varnish, the glazed wall paper used for bath rooms 
 will answer very nicely. Beneath the window should be 
 erected a suitable sink. Its dimensions will vary according to 
 size and quantity of work, but it is best to err in making it too 
 large than too small. The depth should be about eight inches, 
 the width may be anything from eighteen to thirty inches, and 
 the length, from four to six feet. Above it should be two fau- 
 cets connecting with the water main, one of them provided with 
 rubber hose and a rose jet. Where there are no water con- 
 nections, a galvanized iron reservior may be provided, and for 
 experimental purposes, two whiskey barrels, one above the 
 other, the upper one provided with a faucet arranged so as to 
 drain into the lower. Where it is impracticable to place a win- 
 dow in the dark room, artificial light may be used. A gas 
 argand burner with yellow chimney will do very nicely. An 
 oil lamp can also be used, but those sold by photographic stock 
 houses for dry plate work give too feeble a light. A large lamp 
 protected by heavy orange glass is conducive to good work. 
 For experimental work, the window may be covered with yel- 
 low "post office" paper, or an ordinary lamp or gas flame used 
 behind a sheet of glass covered with the same material in such 
 manner as to prevent any white rays from falling in the room. 
 It is of the utmost importance that no daylight enter the dark 
 room except through the orange glass. When it has been com- 
 pleted, the door should be closed, the window covered, and a 
 careful examination made from every possible point of view. 
 Every crack and crevice must be filled or covered, as the least 
 white ray will play havoc with the plate. By the side of the 
 
OF THE SHOP. 
 
 23 
 
 sink should be placed a shelf for the, accommodation of the work, 
 and other shelves should also be placed on the sides of the walls 
 to hold the plate holder, negative glass, developer, collodion 
 vial and bottle, fixing tray and bath holder. For all except ex- 
 perimental work this last should be much larger than actually 
 required. 
 
 The second dark room has no connection with the first, and 
 is used for sensitizing and rolling up zinc plates only. It need 
 not be so dark as the other. For experimental purposes, a dark 
 corner of the room shut off by a yellow curtain will do, but 
 direct sunlight must be excluded. \n the diagram, 12 repre- 
 sents the work table on which is a gas stove for drying the 
 plates; 13, the shelves for bottles, printing frame, etc.; 14, ink 
 slab. The printing frame is kept in this room when not in use. 
 It should be at least one inch larger each way than the nega- 
 tive it is desired to make. For the ink slab, a piece of marble 
 or slate about twice the size of the largest sheet to be etched 
 should be selected. It should be free from flaws or holes. A 
 lithographic roller is generally used, though many prefer one 
 of hard composition. The gas stove need not be large. An 
 ordinary Bunsen burner can be made to answer, or an oil stove 
 substituted. In the etching room, 15 is a bench for stripping 
 negatives, etc.; 16 is the sink; 17, the etching tubs; and in 
 the center is a bench on which is a furnace, 18; marble slab 
 for cooling the plate, 19; powder box, 20; roller and slab for 
 inking up the plate during etching, 21. At the back of the lat- 
 ter are cups for holding gum solution, water, sponge and ink, 22. 
 The part on which the ink slab is placed is about thirty inches 
 high, the rest, thirty-eight. One of the windows should be 
 provided on the outside with a shelf for exposing prints on zinc. 
 The sink need not be large, as it is used only for supplying the 
 etching tubs with water and receiving the wastes. The number 
 and size of the etching tubs will depend entirely upon the quan- 
 tity and kind of work. For small establishments, an ordinary 
 gas burner can be used in place of the oven, which will be de- 
 scribed further on. An old lithographic stone or press bed will 
 answer nicely for the cooling slab. An ordinary box will do 
 for powdering, but one made especially for the purpose, and 
 provided with a lid, is better. The reader is referred to follow- 
 ing chapters for further description of these articles, as well as 
 
24 
 
 ARRANGEMENT AND EQUIPMENT 
 
 rollers, etc., used for gumming up. Many establishments omit 
 the gumming operation, and the beginner need not purchase 
 the materials. In most places the polishing of the zinc is also 
 done in this room. 23 represents a table on which the zinc is 
 cut to size, and on it is also an iron plate for leveling the zinc 
 plates, a pair of callipers and a hammer. 24 is polishing stand 
 with material, and 25, a bench or table for retouching the prints. 
 In large establishments where the zinc is buffed, the buff is 
 placed alongside the polishing table. Experimenters will do 
 well to purchase their zinc already polished. In the finish- 
 ing room, 26 represents the router; 27, the circular saw; and 
 28, the trimmer. The heavy line at the rear of these machines 
 represents the main shaft, which connects with power from the 
 floor below, or a motor. One-half horse-power each for the 
 router and trimmer is sufficient, and one and a half or two-horse 
 power for the saw, according to its construction and condition. 
 As all these tools seldom run at one time, two-horse power will 
 generally be found enough. Large establishments also run 
 their etching tubs with power. At the north wall are the finish- 
 ing benches, 29 being shoot board and plane; 30, blocking plates; 
 31, engraver's table. These benches are about thirty -four 
 inches high. 32 is a proof press; and 33, table for paper, etc. 
 The above plan cannot be followed closely except in rare in- 
 stances, but must be changed according to circumstances. De- 
 tails will be furnished in the following chapters, as well as de- 
 scriptions of many smaller articles which have been omitted. 
 
CHAPTER 111. 
 
 PREPARATION OF CHEMICALS. 
 
 The collodion wet plate method is almost exclusively used 
 for photo-engraving. Dry plates can be utilized, but the first 
 cost, the fact that the glass cannot be used over again, the long 
 time required for development, the necessity of excluding all 
 but feeble red light from the dark room, the long washing which 
 is requisite, and the difficulty in obtaining intensity detract 
 from their desirability. The objections to the collodion method 
 are, the comparatively long exposure required, the fact that 
 every plate must be made immediately before using, that the 
 making of these plates involves considerable skill and experi- 
 ence, and that the silver bath is liable to get out of order ; but 
 these are not as serious as would at first appear. Unlike por- 
 trait photography, the object remains still, and therefore is not 
 liable to make a blurred image, and while one plate is being 
 exposed the operator can prepare another. A duplicate silver 
 bath and a little experience will overcome the other objections, 
 and if there were no other reason, economy alone would dictate 
 its choice. The compounding of the 
 various preparations used in photo- 
 graphy should be done in the photo- 
 graphing room at a bench near the 
 sink. Army scales, illustrated in 
 Fig. 7, are accurate enough for the 
 purpose. It is seldom necessary to 
 weigh more than one ounce at a 
 time, and weights from one grain 
 up to one ounce Troy should be pro- 
 vided. Many prefer dispensing scales shown in Fig. 8, as they 
 are easier to handle. If the business is such that preparations 
 must frequently be made up, it is best to cut pieces of glass or 
 metal into weights agreeing with quantities required. Paper 
 labels should be pasted upon them, on which are written the 
 
26 
 
 PREPARA TION OF CHEMICALS. 
 
 weight and the chemical to be weighed off ; thus, " Bromide of 
 zinc 75 grains." This will save time in looking up formula and 
 adding together small weights. Although all formulae call for 
 Troy ounces, containing 480 grains, chemicals are always sold 
 
 Fig. 8. 
 
 by Avoirdupois weight, an ounce having but 437^ grains. For 
 measuring fluids, two graduates, three and sixteen ounce, should 
 be purchased. Also two funnels, pint and half gallon (the lat- 
 ter reserved for the silver bath), and a funnel stand for holding 
 them. It will not pay to economize on these, even in a small 
 place. Better have three or four funnels of various sizes, and 
 if one is reserved for each preparation it will pay in the end. 
 Few photographers now use filtering paper. Absorbent cotton 
 is cheaper, works more rapidly, is easier to use, and, except for 
 special purposes which will be enumerated further on, just as 
 good. A special silver hydrometer should be used for measur- 
 ing the quantity of silver in the bath, and if it is desired to test 
 the intensity of other liquids, hydrometers for liquids heavier or 
 lighter than water can be obtained. All these articles should 
 be kept on a shelf above the compounding bench. 
 
 The utmost care should be taken in the selection of the 
 chemicals. Those sold by drug stores are seldom of the right 
 quality. Procure them from some photo-engravers' supply es- 
 tablishment. Beginners are advised to purchase their prepara- 
 tions made up, as it will enable them to center their attention 
 on the manipulation. Afterwards the formula may be obtained 
 and the preparations made up as opportunity offers. Impure 
 water is a frequent source of trouble. Usually tap water will 
 answer very well, but if not clear it should always be filtered. 
 If there is any doubt as to its purity, use distilled water, which 
 costs very little. 
 
PREPARATION OF CHEMICALS. 
 
 27 
 
 COLLODION. 
 
 Collodion is generally made first, as it seldom works well 
 when first prepared and always improves with age. The best 
 way is to add to the pouring vial, every evening, a little collo- 
 dion which has not yet been used, but has aged, or as photo- 
 graphers express it, "ripened," for several weeks. Almost 
 every photographer has a recipe which he considers better than 
 all others. If you know one who is producing good results for 
 photo-engraving purposes, you need not hesitate to accept his 
 formula under his guidance, but do not experiment with several 
 before youarethoroughly acquainted with the possibilities of one. 
 This is a mistake beginners are very apt to make. While the 
 advice and assistance of an experienced collodion photographer 
 are of much help, it should be remembered that the conditions 
 of portrait and landscape photography are entirely different from 
 those of photo-mechanical engraving. 
 
 The following is a recipe which has proven of worth in a 
 number of establishments : . 
 
 Alcohol, 15 ounces. 
 
 Ether, sulph. cone, 20 ounces. 
 
 Gun cotton, 280 grains. 
 
 Bromide of Zinc, 75 grains. 
 
 Iodide of Zinc, i75 grains. 
 
 Alcohol, 5 ounces. 
 
 Absolute alcohol is quite expensive, and many photographers 
 use a good quality, 98 per cent. Wood alcohol will not answer. 
 The ether should be concentrated sulphuric. There are a num- 
 ber of brands in the market, so it should not be purchased at a 
 drug store. Almost all works on photography describe methods 
 of making the gun cotton, which differs from the commercial 
 article, being inexplosive and entirely soluble in alcohol and 
 ether, but its preparation involves such care and experience 
 that the photo-engraver would find it impossible to make a uni- 
 form article. Competition has brought down the price so that 
 even the largest establishments now purchase instead of making 
 it. The finer qualities, though costing a little more, will pay 
 for themselves in the end, and are especially recommended to 
 beginners. Cellodine is an excellent substitute. The zinc salts 
 should be fresh and of the best quality. Take a seven-pound 
 bottle, perfectly clean, and pour into it the amount of alcohol 
 
28 
 
 PREPARATION OF CHEMICALS. 
 
 given in the first lialf of the formula, then add the cotton or cel- 
 lodine. Shake well and stir occasionally, particularly if you 
 have used the latter, otherwise the cellodine will form a jelly- 
 like mass which is difficult to dissolve. After a short tinie, add 
 the ether and shake well until there is no longer any undissolved 
 solid, then set away to clear. Put the bromide of zinc in a glass 
 or porcelain mortar, which should be perfectly clean, and add a 
 few drops of alcohol so that you can grind it to a paste. Con- 
 tinue to add alcohol until it has taken up as much bromide as it 
 will dissolve, allow it to settle a few moments and pour into a 
 clean sixteen-ounce bottle. Continue adding alcohol and pour- 
 ing it off until the bromide is entirely dissolved. Do the same 
 thing with the iodide, for which there will be enough alcohol 
 left, unless too much has been used for the bromide. If such is 
 the case, add a few drops of distilled water, but no more than 
 necessary. The contents of the sixteen-ounce bottle, which 
 will appear somewhat milky, are now filtered into the plain col- 
 lodion, which is then again well shaken and set aside for a few 
 days to settle. When perfectly clear and transparent it may 
 be drawn off for use. The following is another excellent recipe 
 which gives intense negatives and ripens somewhat quicker : 
 
 Alcohol, 20 ounces. 
 
 E^her, 20 ounces. 
 
 Gun cotton, 280 grains. 
 
 Iodide of Ammonium, 160 grains. 
 
 Bromide of Cadmium, 80 grains. 
 
 Chloride of Calcium, 80 grains. 
 
 It is prepared in exactly the same manner as the first, a few 
 ounces of the alcohol being reserved for dissolving the salts. 
 
 New collodion unmixed with old sometimes makes foggy 
 negatives. Adding a few drops tincture of iodine (resublimed 
 iodine i ounce, alcohol 8 ounces), sufficient to make it a light 
 red color, will make it work free from fog, and yet give perfect 
 intensity. Ether evaporates much more rapidly than alcohol. 
 If the collodion be too thick it should be thinned with concen- 
 trated sulphuric ether only. It should, however, be thicker 
 than that used for portrait photography. An excess of ether 
 makes a tough, horny film, but prevents intensity. An excess 
 of alcohol makes the film rotten, but increases intensity. 
 
PREPARATION OF CHEMICALS. 
 
 29 
 
 THE SILVER BATH. 
 
 Every plate which is sensitized takes a certain amount of 
 silver from the bath and adds impurities. For this reason the 
 quantity and the holder should be as large as possible, so that 
 the change will be slow. As it is liable to give out without a 
 moment's warning, a duplicate bath of the same quantity should 
 always be kept ready, unless you are confining yourself to ex- 
 perimental work and can afford to wait several days in case of 
 a mishap. Though the first cost is more, a large bath is less 
 expensive to run than a small one, as it will require less "doc- 
 toring." The bath holder. Fig. 9, 
 should be of glass encased in a 
 wooden box having a hinged cover. 
 Porcelain will, however, answer nice- 
 ly, but the hard rubber baths some- 
 times sold for this purpose are not de- 
 sirable, as they quickly foul the bath. 
 For the same reason a dipper of silver 
 wire is preferable, but hard rubber is 
 almost universally used. The nitrate 
 of silver should be triple fused, as sold 
 by supply houses for this purpose. 
 Cheap grades contain impurities, and 
 are dear at any price. Pour into a large white bottle enough 
 distilled water to fill your bath holder, add the nitrate of silver 
 until sufficient has dissolved to make it register 40 grains to the 
 ounce with the silver hydrometer. This may be observed by 
 thoroughly shaking the contents and pouring a little of the solu- 
 tion into the tube which accompanies the hydrometer. Care- 
 fully place the latter into the tube, and when it floats quietly, 
 note the figure at the surface of the liquid. If it registers below 
 40, nitrate of silver must be added; if above, more distilled 
 water. Roughly, it will require about twelve ounces nitrate of 
 silver to make one gallon of bath. When it registers correctly, 
 test with a strip of blue litmus paper. If the color remains un- 
 changed, and distilled water was not used, expose to the sun 
 for a few days, when all organic impurities will be precipitated 
 in the form of black powder. If the color of the litmus paper is 
 changed to red, the silver was not properly made and contains 
 free acid, in which case concentrated water ammonia should be 
 
 Fig. 9- 
 
30 
 
 PREPARATION OF CHEMICALS. 
 
 added a few drops at a time, under constant stirring, until the 
 paper is clianged back to its blue color before exposing to the 
 light. When clear, filter into the bath holder and add nitric 
 acid, C. P., a few drops at a time, until the blue litmus paper 
 dipped into it acquires a decidedly red color. Do not add too 
 much acid and stir constantly while so doing. 
 
 Allow it to rest again for a few hours, when it will be ready for 
 iodizing. This can be done by adding iodide of potash, but most 
 photographers.prefer to do so by coating a glass plate with col- 
 lodion in exactly the same manner as if sensitizing it for a nega- 
 tive, and lowering it into the bath holder with the dipper. 
 Directions for this will be found in the next chapter. The film 
 will at first become translucent and creamy, but on removing 
 it after a few hours will again be perfectly transparent, the 
 bath having dissolved the salts from the collodion. One large 
 plate is generally sufficient to iodize the bath, but, on trial, 
 should the resulting negative be found of a bluish color and 
 foggy in the lights the above operation must be repeated. Do 
 not over iodize the bath until you are certain the fog is caused 
 by it. Directions for correcting faulty baths will be given in 
 •Chapter V. 
 
 THE DEVELOPER. 
 
 ^^^^''j i6 ounces. 
 
 Sulphate of Iron, i ounce. 
 
 Acetic Acid No. 8, 2 ounces. 
 
 Alcohol, I ounce. 
 
 The sulphate of iron (sometimes called persulphate) and 
 acetic acid should be of a high grade, but need not be chemically 
 pure. Place the water in a bottle, add the iron and shake until 
 it is dissolved, then add the acetic acid, shake again, and filter 
 through a plug of absorbent cotton pushed into the neck of a 
 funnel. After a few days this developer will become darker 
 and sediment will form at the bottom. This will not impair its 
 usefulness, though the sediment should be removed by filtering. 
 
 FIXING SOLUTION. 
 
 Cyanide of potassium, i ounce. 
 
 ^^^^■"j 6 ounces. 
 
 The cyanide of potassium should be fused and of good 
 quality. Break it up into small lumps and place it in a bottle 
 with the water. Shake until dissolved, when it is ready for 
 
PREPARA riON OF CHEMICALS. 
 
 31 
 
 use. This solution loses strength from use, and should fre- 
 quently be replaced with new. It is extremely poisonous, and 
 the fumes, which are stronger in warm weather, should be 
 avoided as much as possible. 
 
 INTENSIFIER. ^"^^ 
 No. I. _/ 
 
 Saturated solution bichloride of mercury, ... 8 ounces. 
 
 Chloride of ammonium, 2 ounces. 
 
 Water is preferably distilled. The chemicals should be 
 pure. A small amount of bichloride of mercury should always 
 remain at the bottom of the stock bottle. When the water will 
 take no more, add the chloride of ammonium, shake thoroughly 
 and filter. This solution also is poisonous. It should be occa- 
 sionally filtered, and strengthened by the addition of new solu- 
 tion. 
 
 No. 2.' 
 
 Hydrosulphuret of ammonium, i ounce.. 
 
 Water, 5 ounces. 
 
 The ammonium comes in the form of a heavy liquid and 
 has a disagreeable odor. It should be mixed with clear water. 
 As it decomposes on contact with the atmosphere, it should be 
 prepared freshly each day. 
 
 CLEARING SOLUTION. 
 
 Water, Bounces. 
 
 Nitric Acid, CP., i dram. 
 
 Mix together in a bottle. 
 
 STRIPPING SOLUTIONS. 
 
 It will generally be better to purchase these preparations, 
 particularly the first, as making it involves considerable skill. 
 Rubber stripping solution is made by putting into a wide 
 mouthed bottle a quantity of perfectly pure and unvulcanized 
 rubber cut into small bits, and covering the same with benzole. 
 After a few hours the rubber will swell into a jelly-like mass. 
 More benzole must now be added, under constant shaking, until 
 a liquid the consistency of molasses is formed. This will take 
 several days, the period varying greatly, according to the purity 
 and freshness of the rubber. When of the proper consistency 
 it should be filtered through cheese cloth. It is then ready for 
 use. Do not expose to the sun, as this has a tendency to thin 
 the solution permanently. It gradually loses its tenacity, and 
 
32 
 
 PREPARATION OF CHEMICALS. 
 
 no more should be prepared than will last six months, if too 
 thin, it may be thickened by the addition of rubber or the eva- 
 poration of the benzole. If too thick, benzole must be added. 
 This solution dries rapidly, but as benzole is quite expensive, 
 many prefer to dissolve the rubber in benzine, which dries 
 much slower. There are many grades of this article on the 
 market. That which is usually sold under that name is not fit 
 for the purpose. 
 
 Stripping collodion (No. 2) is made by dissolving thirty 
 grains of gun cotton in three ounces of alcohol, and adding three 
 ounces of ether and one dram of castor oil. The gun cotton 
 need not be of as good quality as for negatives. The ether 
 should be concentrated sulphuric, and 95 per cent, alcohol will 
 do very well. Allow the mixture to settle until it is perfectly 
 clear, when it is ready for use. The rubber stripping solution 
 will have somewhat the color of muddy water, the collodion, 
 almost white, but both when applied to a glass should give a 
 perfectly clear and transparent coating. If only slightly tinted 
 yellow, green or red, the printing quality of the negative will 
 be seriously impaired, and better materials must be secured. 
 
CHAPTER IV. 
 
 Manipulation. 
 
 As the glass is used repeatedly, it will pay best to purchase 
 that of a superior quality. Chance's twenty-six ounce English 
 glass is the best, it being freer of flaws and straighter than any 
 other. Next in quality to this is genuine French negative glass. 
 American glass, though considerably cheaper, is so full of flaws 
 that its use is not economical. The sizes generally used are 
 eight by ten, ten by twelve, eleven by fourteen and fourteen 
 by seventeen inches. Even for small work it will pay to make 
 a plate eight by ten inches. Before using the glass the rough 
 edges should be removed with a file, otherwise there is danger 
 of cutting the fmgers. It is of the utmost importance that the 
 glass be perfectly clean. Plates which have been used or new 
 plates may be laid in a tub or stone jar kept beneath the sink 
 containing a can of concentrated lye dissolved in two gallons of 
 water. A few hours before they are to be used, take them out 
 and wash thoroughly under the tap. When all traces of lye 
 have been removed, place the plate in another jar containmg 
 one gallon of water and eight ounces of nitric acid. After sev- 
 eral hours, remove the plate and again wash thoroughly, first 
 beneath the tap and afterwards with distilled water, and then 
 polish clean with Joseph paper. Many prefer to hold the glass 
 in a wooden vise while so doing. Lastly, put it on a negative 
 rack, in a clean place, to dry. Avoid touching the plate with 
 the fingers after it is clean. The slightest particle of dirt or 
 dust will make a faulty negative. A good test for cleanliness 
 is to breathe on the plate. If the moisture disappears evenly 
 the plate is clean, but if it clings to any spot it must again be 
 polished with a paper or chamois skin. Obstinate grease spots 
 may sometimes be removed with alcohol. The use of polishing 
 material, such as rouge or chalk, should be avoided, as it will 
 adhere to the edges and eventually disorder the bath. To avoid 
 trouble from the film leaving the glass, dip a small wad of cot- 
 
34 
 
 MANIPULA TION. 
 
 ton in rubber stripping solution and run it around the edges of 
 the glass on the side to be collodionized so as to cover a strip 
 one-fourth of an inch wide. Be careful to get none on the rest 
 of the glass, and make the coating as thin as possible. Unless 
 the glass is perfectly straight, select the concave side. A num- 
 ber of plates may be prepared in this manner, as they will keep 
 for any length of time. Some photographers prefer to use albu- 
 men in place of the rubber solution. It is made by beating up 
 the white of an egg, adding twenty ounces of water and again 
 beating. When the solution has settled and has been filtered, 
 it may be applied with a wad of cotton as above directed, or 
 with a soft brush at the side of which is attached a stick as a 
 guide. To avoid the mistake of collodionizing the wrong side 
 of the glass, the edges of which have not been treated, pieces 
 should be placed to face the same way in the rack. In case 
 there is any doubt, breathe upon the surface, when the differ- 
 ence between the clear and coated glass will at once be made 
 apparent. 
 
 If you can get some collodion photographer to show you 
 how to manipulate the plate you will save a good deal of trouble, 
 otherwise pour a few ounces of collodion into the collodion 
 vial, dust off a piece of glass carefully with a fine camel hair 
 brush, hold it with the thumb and 
 two first fingers by the corner C, as 
 shown in Fig. lo, and, going to the 
 dark room door so that you will have 
 good light, pour a quantity of collo- 
 dion near the center of the plate, 
 covering about two-thirds of it ; in- 
 cline the glass so that the pool will 
 run to the corner A, clear to the ' Rg. lo. 
 edge but not over it, then incline it so that it will run towards 
 B, C, and finally D. Do not breathe upon the plate while so 
 doing. If the plate is a large one the center may be supported 
 on a bottle from the neck of which a clean cork projects. Sup- 
 porting with the fingers is likely to warm the plate and cause 
 spots at these places in the finished negative. Hold the plate 
 so that the corner D is slightly lower, and pour the surplus back 
 into another wide-mouthed bottle reserved for this purpose, 
 as in Fig. II. These drippings may afterwards be filtered 
 
MANIPULA TION. 
 
 35 
 
 Fig. II. 
 
 back into the pouring vial. While draining, the plate 
 
 should be held at an angle of fifteen degrees, which should 
 
 gradually be increased until the greater 
 
 portion has drained off. As it begins 
 
 to set, the plate must be rocked with 
 
 a gentle motion so that the coating will 
 
 be as uniform as possible. This is 
 
 done by moving the hand which holds 
 
 the bottle, and also the plate in the 
 
 neck of the draining bottle, so that the 
 
 point A moves towards E. If this is not 
 
 correctly done the plate will have waves 
 
 on the coating, and will be much thicker 
 
 in one portion than in another. The bottles are now stoppered and 
 
 put aside. Many photographers do not drain all the surplus 
 
 into a bottle, but wipe off the ridge which forms at the bottom 
 
 edge with their fingers. As the plate dries it should gradually 
 be made to assume a perpendicular position, the rocking being 
 continued until the collodion sets and becomes the consistency 
 of soft wax, which may be noticed from its appearance. It can 
 also be determined by pressing the thumb against the corner of 
 the plate where the collodion was poured off. If an impression 
 is retained, and the collodion shows no tendency to leave the 
 plate, it has set to the proper degree. Always wipe the mouth 
 of the vial before and after using. The lid of the bath holder 
 box is now raised, the dipper pulled out and the edge of the 
 plate A B laid on the projections at the bottom of the dipper, 
 which is then lowered at a moderate speed. Unless this is done 
 steadily without stoppages, there will be streaks across the fin- 
 ished negative. It is best that the plate holder should not allow 
 the plate to come within an inch of the bottom, otherwise the 
 sediment which accumulates in the bath may produce pin holes 
 on the plate. A peg can be placed in the handle of the dipper 
 so that it will rest against the top of the holder and prevent the 
 plate from going in too far. Now close the lid of the bath holder 
 and the dark room door. 
 
 It is presumed that the camera is in position on the swing 
 or stand, with the lens in the center of the lens board, and that 
 the copy has been pinned up somewhere near the middle of the 
 copy board. It is also to be supposed that the copy is good— 
 
36 
 
 MANIPULA TION. 
 
 clear black lines against a dull white surface. Do not attempt 
 to make a very large or difficult job at the beginning. If you 
 are also to furnish copy you will do well to consult "Copy for 
 Photo-engraving." In fastening on the copy, see that the tacks 
 do not throw shadows which interfere with the drawing. Now 
 put your eyes close to the ground glass and cover your head 
 with a piece of cloth so as to exclude all light, shift the camera 
 and bellows until the image upon the ground glass is the size 
 you wish the cut. Do not attempt to reduce it much on the 
 first trial. Finally, the screw or lever at the back of the camera 
 must be moved gently until, when examined with the focusing 
 glass, the image is sharp, clear and evenly lighted. Focus half 
 way between the center and edge of the drawing. A good 
 focusing glass is highly desirable. Some experts dispense with 
 it, but this is not advisable. While focusing, put the diaphragm 
 having the largest hole, in the lens. When the image is per- 
 fectly clear and distinct, take out the large diaphragm and sub- 
 stitute a smaller one. This will make the image sharper by 
 excluding the outside rays, and will necessarily make the ex- 
 posure longer. For a small cut which occupies the center of 
 the field, the second or third size stop may be used. Now put 
 the leather cap on the lens, return to the dark room and close 
 the door. Turn back the cover of the bath holder, raise the 
 dipper gently, and when the plate projects sufficiently, grasp it 
 by one of its corners and allow the surplus fluid to drain back 
 into the bath. It generally takes four or five minutes to sensi- 
 tize a plate. If, on taking it out, it appears of an even, creamy 
 color, and the surface smooth and glassy, it may be removed. 
 If, however, it is streaky, and the solution looks as though it 
 was running over a greasy surface, it must be carefully replaced 
 in the bath and moved about in an easy circular motion. The 
 plate should be allowed to remain in the bath at least a minute 
 after the greasy appearance has left it. When it presents a 
 satisfactory appearance, drain by leaning it on the shelf with 
 the upper edge against the wall, the lower edge resting against 
 a pad of blotting paper. The edge which was lowest while 
 flowing on the collodion, and at the top when in the bath, must 
 be at the top while draining. Allow the plate to rest for a short 
 time on the blotting paper. The period will vary with the size 
 of the plate, two minutes being about right for an eight by ten. 
 
MANIPULA TION. 
 
 37 
 
 While it is draining, wipe the back dry with another piece of 
 blotter. It is then ready to be placed in the plate holder. If 
 this is of the old type, you can readily see into which kit it will 
 fit. If it is a Bonanza or Benster holder, the trough must be 
 raised so that the plate will be in the center of the holder. Now 
 place the plate so that the sensitized side is towards the front, 
 then close and fasten the door. In all these operations be care- 
 ful not to turn the plate so that the silver solution will flow 
 back over it. Make sure that the slide is in its place and carry 
 it in an upright position to the camera. Remove the ground 
 glass, lay it in a safe place, and put the holder in the position 
 before occupied by it. Now put the camera cloth over the holder 
 and pull out the slide steadily, letting the cloth cover the aper- 
 ture. If this starts the camera swinging, steady it before re- 
 moving the cap from the lens. The length of exposure will de- 
 pend upon the light, make of lens, and size of diaphragm, vary- 
 ing from three to twenty minutes. The advice of a photogra- 
 pher will be of much assistance to you at this point. If you 
 have no one to help you, better make a number of negatives 
 with the same light, giving various exposures and noting the 
 results, or first pull the slide only half way out, so that part of 
 the plate will be exposed longer than the rest. After exposure, 
 place the cap on the lens and shove in the slide squarely. If 
 one corner is pushed in first, it may open the shutter and allow 
 the light to shine on the plate. Carry the holder into the dark 
 room, holding in the same position as when it was exposed. Set 
 it in its place on the shelf, close the dark room door and win- 
 dows, and remove the plate from the holder. Hold it by the 
 same corner as when flowing on the collodion, but keep the 
 edge which was at the top of the holder and bath slightly above 
 the others, otherwise the small amount of surplus silver solution 
 which may have accumulated while the plate was at rest may 
 flow back on the plate and stain the image. Previous to enter- 
 ing the dark room, see that the developer is in good condition 
 and ready for use. A glass beaker makes a good pourer. Hold 
 it with the left hand, its mouth close to the edge opposite that 
 by which the plate is held, and with a quick motion pour out 
 the solution so that it will flow over the plate in one even wave. 
 If this is done hesitatingly the development will be uneven. 
 Care should, however, be taken that no more developer runs 
 
38 
 
 MANIPULA TION. 
 
 over the edge than can be avoided, otherwise silver will be car- 
 ried away and the resulting plate be weak. Now hold the plate 
 in a horizontal position, and rock gently from side to side so as 
 to keep the developer constantly moving. The image will 
 gradually appear. If the exposure was correctly timed it will 
 take about six or eight seconds, the whites or lightest parts of 
 the copy first making their appearance. When you can see 
 the finest details distinctly, the development must be stopped. 
 If not carried far enough, the finer lines will not print clearly, 
 and the background will not be sufficiently opaque. If over- 
 developed, the lines will become fogged or filled up. If you 
 have not allowed sufficient time for exposure, the effect will be 
 the same as if under-developed, except that in addition some of 
 the finer details will be entirely lost, and it will take longer to 
 develop the image. If over-exposed, the image will flash up as 
 soon as the developer is poured upon it, and on intensifying the 
 fine lines will be filled. It sometimes happens that the plate 
 has been under-exposed. This may be noticed by the length 
 of time taken for development, as well as the weakness of the 
 image. Should the plate have been over-exposed, adding a 
 little more alcohol to the developer will retard its working and 
 improve the plate. As the bath acquires alcohol from the col- 
 lodion the developer will refuse to flow evenly on the plate, the 
 film repelling it as though it were greasy. Adding a very little 
 alcohol to the developer will overcome this difficulty. A better 
 way is to simmer down the bath in a porcelain dish until it has 
 been reduced to half its volume, and then add distilled water 
 until it registers forty degrees on the hydrometer. 
 
 The plate is now ready for fixing. On account of its poison- 
 ous nature, many prefer to keep this solution in a bath holder, 
 lowering the plate into it as when sensitizing. Generally it is 
 poured off and on the plate until the yellow color disappears. 
 After each day's work, a small piece of cyanide of potash may 
 be added to retain its proper strength, if not strong enough, 
 the lines will not clear properly, and are liable to fill up when 
 intensifying. If too strong, the negative will not be sufficiently 
 intense and will clean the plate instantly instead of gradually. 
 After fixing, the plate is again washed off under the tap until 
 the last trace of cyanide is removed. It is then placed in a tray 
 which contains the No. i intensifier, and allowed to remain 
 
/ 
 
 MANIPULA riON. 39 
 
 until the film turns white. If the plate has been properly ex- 
 posed it will take about ten or fifteen minutes to do this. Never 
 intensify in the dark room; a bench near the sink is the best 
 place. This operation will not require watching. When the 
 plate has bleached white it is removed, the surplus solution 
 being allowed to drip back into the tray. It is again thoroughly 
 washed. This takes considerable time, as the bichloride of 
 mercury does not easily dissolve in water. Ten minutes under 
 the tap is none too long, and if more time can be allowed it will 
 do no harm. Now pour on the No. 2 intensifier in an even 
 wave, as directed with the developer. This will immediately 
 turn the film an intense black. Leave it on until the color has 
 penetrated through the glass, then wash it off at once. The 
 clear spaces will now have a slightly yellowish or greenish ap- 
 pearance. To remove this, pour the clearing solution on and 
 off until the lines are perfectly transparent, pouring the surplus 
 solution back into the bottle. Should the resulting negative be 
 imperfect in any respect, some one of the manipulations has 
 been faultily performed, or the chemicals and apparatus were 
 not in perfect condition. These faults will be treated in the next 
 chapter. After the plate has again been washed it is placed in 
 the rack to dry. If the drawing was left-handed, the negative 
 may be at once used for the printing on zinc. As generally 
 made, the cut would be reversed, i. e., print would read from 
 right to left. To correct this the film must be stripped from the 
 glass and fastened to another piece upside down, that is, the 
 side coated with stripping solution next the glass. When 
 entirely dry, rubber stripping solution is poured upon it so as to 
 cover such portions of the plate as are intended to be used. Pour 
 the surplus back into the bottle and place the glass on a level 
 shelf to dry, where no dust will get at it. When it no longer 
 feels tacky, collodion stripping solution is poured on it in the 
 same manner. During both operations the plate should be 
 rocked to prevent streaks. It will take but a few minutes for 
 this to dry thoroughly. Now cut around the picture with a pen- 
 knife so as to leave one-fourth inch margin around the design. 
 Be careful to cut clear through to the glass, and lay the plate in a 
 tray containing barely enough clean water to cover it well. In 
 a few moments the film will commence to part from the glass 
 without any assistance. In the meantime, carefully clean a. 
 
40 
 
 MANIPULA TION. 
 
 piece of glass for stripping. Thin plate-glass one-fourth of an 
 inch in thickness, or twenty-six ounce English glass, should be 
 used for this purpose. Place one edge in the tray containing 
 the negative, then lifting the film, turn it upside down and lay 
 it in the center of the glass. If a number of negatives of a 
 similar class of work have been prepared, they may be attached 
 to the same piece of glass. With the aid of the finger tips, or 
 preferably a rubber squeegee, smooth the film to the surface of 
 the stripping glass, being careful to avoid wrinkles or folds. If 
 undue force is exercised, you are liable to tear the film or draw 
 it out of shape. The squeegee consists of a strip of very soft 
 rubber six or eight inches long fastened to a wooden handle. 
 A weather strip can be made to answer, but being compara- 
 tively rough it is liable to injure the film. If the stripping col- 
 lodion was made according to the formula given, and the manipu- 
 lations were carefully performed, the film will adhere to the 
 glass smoothly and closely. Should it show a tendency to curl 
 away, the albumen solution used for coating the edge of the 
 plate, as directed in the preceding part of the chapter, should 
 be poured upon the surface of the glass, and the film squeegeed 
 upon it. Generally a failure in this direction may be attributed 
 to insuificient cleaning of glass. The film must be allowed to 
 dry, when it is ready for printing. Films may be stripped from 
 the glass and kept between the leaves of a clean book. If care 
 is taken to prevent folds or wrinkles they will keep in this con- 
 dition for years, and can be printed at convenience. Trans- 
 parent celluloid may with advantage be substituted for the strip- 
 ping glass, its flexibility insuring contact without danger of 
 breakage. 
 
CHAPTER V. 
 
 Defective Negatives and Their Causes. 
 
 The beginner generally experiences his greatest difficulty 
 with photographing. Bath and collodion seldom act well when 
 new. Even after everything is in perfect running order, fail- 
 ures often result without apparent reason, if you cannot ob- 
 tain the advice and assistance of a professional, be sure you 
 have located the fault before you attempt to correct it, other- 
 wise you will only increase the damage. Never dust out the 
 dark room, but wipe it out occasionally with a damp cloth. It is 
 well to sprinkle the floor to prevent dust from being raised by 
 walking upon it. 
 
 The greatest trouble is the so called "fog," which makes 
 opaque or only translucent such parts of the negative as should 
 be perfectly clear and transparent. The fumes of ammonia and 
 hydrosulphuret of ammonia will always cause fog. These 
 chemicals, and preparations containing them, should never be 
 allowed within the dark room. Escaping sewer gas, coal gas, 
 and the gases produced by the combustion of coal oil and gas, 
 will sometimes cause fog, but can usually be located and avoided 
 with little trouble. If, on holding the finished negative to the 
 light, the lines are not free from every trace of color or mist, 
 test the bath with blue litmus paper, if the paper remains un- 
 changed, add nitric acid C. P., under constant stirring, until 
 the paper has changed a decided red. After a short rest the 
 bath will be ready for use. Do not make the mistake of adding 
 too much acid, otherwise the trouble will only be increased. A 
 newly prepared bath which fogs slightly will often give perfect 
 negatives after a night's rest. If the bath gives an acid re- 
 action, collodionize and sensitize a plate and proceed to develop 
 and fix it without exposure in the camera. Unless the plate 
 is perfectly clear, the fog was probably caused by white light 
 entering the dark room, or by the collodion. First test for light, 
 
42 
 
 DEFECTIVE NEGA Til E:S 
 
 carefully looking over every portion of the dark room to see 
 that no stray rays are admitted. Holes or cracks must be cov- 
 ered with paper. If your light comes from a window, cover it 
 with another sheet of heavy orange paper or glass. If from a 
 lamp, substitute a small candle and try again. If the plate still 
 fogs, it is probably due to the collodion being alkaline. Add a 
 few drops tincture of iodine, or enough old collodion to give it 
 the color of Maderia wine. If this does not remove the fog the 
 developer is probably too strong. This can be detected by the 
 image on an exposed plate making its appearance too rapidly. 
 Dilute it with a mixture of acetic acid No. 8, two ounces; dis- 
 tilled water, eight ounces. It sometimes happens that during 
 development an irridescent coating of silver floats upon the 
 surface of the developer in constantly changing spots. This 
 must be washed off, otherwise it will settle on the collodion and 
 make a foggy plate. The cause is obscure, being probably a 
 lack of harmony in the preparations. When water is supplied 
 from a wooden tank it often happens that it becomes contami- 
 nated, in which case its use will cause fog. If in doubt, try 
 distilled water in its place. If the unexposed plate develops 
 without trace of color, the cause must be sought outside the 
 dark room. Prepare a fresh plate, place it in the camera, draw 
 out the slide (leaving the cap on the lens), expose for five 
 minutes, then take it back to the dark room and develop. If 
 the plate has fog, the cause is a defective camera or plate holder. 
 
 admitting light. This can easily be located 
 and remedied. Generally it is not evenly 
 distributed, but in the form of streaks. If 
 this plate also is clear, and if the copy 
 consists of black lines upon a white back- 
 ground, the cause is probably over-exposure. 
 This is by far the most frequent cause of 
 fog. It can usually be detected by the de- 
 velopment being much more rapid than 
 normal. Try another negative with shorter 
 
 Fig- exposure. If, however, this plate also is 
 clear, the cause is reflected light entering the lens. Cut a 
 piece of card-board into the shape of Fig. 12, stain the inside 
 black and fasten it to the lens, as in Fig. 13, moving it around 
 so as to cut off all light. It would be safer to put the guard 
 
AND THEIR CAUSES. 
 
 43 
 
 completely around the lens, but this will make it awkward for 
 putting on and removing the cap. The above directions will 
 locate the reason of the fog, 
 except such as is caused by 
 under or over-development, too 
 strong fixing solution, and al- 
 lowing the glass to remain too 
 long in the No. 2 intensifier. 
 Judgment as to the length of 
 development can only be ac- 
 quired from experience. The i?- 
 other causes can be located by watching the progress of the 
 plate. 
 
 Should the film vary much in intensity, and the corners be 
 lighter than the center, it was caused by the use of too large a 
 diaphragm. If any part of the plate is less intense than the 
 other, and always the same part, it is caused by uneven light- 
 ing of the copy. If the daylight enters from the window, or if 
 you are using electric light, this is almost sure to be the case at 
 the beginning. Reflectors made of white paper and mounted 
 on suitable stands must be placed so as to equalize the light, 
 and the camera stand must be moved according to circum- 
 stances. Use a small diaphragm while trying the light. Careful 
 experiment alone will determine the size and angle of the reflec- 
 tors. If the inequalities vary in position, they are probably 
 caused by uneven films of collodion. Indistinct negatives are 
 often caused by lack of care in focusing, or by imperfect ap- 
 paratus in which the ground glass and sensitized plate do not 
 occupy the same position. Spots and stains often make their 
 appearance, sometimes without apparent cause. Above all, 
 keep your hands and apparatus perfectly clean. If you allow 
 dust to accumulate in the dark room, it will make small spots 
 or "pin holes" in your negatives. If dust accumulates in the 
 camera, it may be set in motion by the current of air started 
 by putting the plate holder in position. Should it settle on the 
 plate while you are coUodionizing it, or should the collodion be 
 unsettled, the spots will have small tails termed "comets" by 
 photographers. The remedy is to clean the dark room and 
 filter or settle the collodion. Setting the plate holder down 
 with force or driving the slide in with a jerk will cause the un- 
 
44 
 
 DEFECTIVE NEGATIVES 
 
 combined silver solution to splash on the surface of the collo- 
 dion, and result in spots ending on one side with a point. A 
 drop of water falling on the plate while flowing will give an 
 irregular shaped spot which appears to be rough. If the bath 
 has become over-iodized from constant dipping, numerous pin 
 holes will be found distributed over the entire surface. When 
 examined with a magnifying glass they will be found to be small 
 crystals, and without tails, in this respect differing from those 
 caused by dust or unsettled collodion. The remedy is to cor- 
 rect the bath as directed in the last part of this chapter. Should 
 the developer be too strong, it may make pin holes very much 
 resembling those last described. When the cyanide of potash 
 in the fixing solution has absorbed as much silver as it can, it 
 also will deposit fine crystals on the plate, much like those last 
 mentioned, but as these do not make their appearance until fix- 
 ing, the cause can easily be located and remedied by using new 
 fixing solution. Small, brown spots of a star-like character are 
 caused by not washing off all the developer before fixing. If 
 the plate be covered with irregular marks somewhat the shape 
 of oyster shells, or whitish insensitive spots, it is caused by ex- 
 posing the plate so long that parts have dried out. The remedy 
 is to secure more light or a better lens, so that you will not re- 
 quire so much exposure, hi very warm weather, placing a 
 sheet of wet blotter behind the plate and in contact with it 
 while exposing in the camera will help, by retarding evapora- 
 tion. New baths sometimes produce marks in the shape of 
 oyster shells, but after a few negatives have been made they 
 will disappear. If the developer be too strong, or if it be not 
 flowed on with a perfectly even wave, it will cause streaks and 
 stripes at once apparent. If thrown on with force, it is likely 
 to make a spot at the point of contact, with lines radiating from 
 it. Should the collodion be too strongly salted, a scum will 
 form on the surface of the bath which will adhere to the plate 
 and cause zigzag lines to appear all over its surface. It can be 
 cured by adding plain collodion to the vial, but if the plate be 
 rapidly withdrawn from the bath the scum is not so liable to 
 adhere. An air bubble in the collodion will make a narrow, curved 
 mark. Such plates should not be sensitized, as the negative 
 will surely be defective. Should the film be mottled and have 
 a clouded appearance, the collodion is too thick or the coating 
 
AND THEIR CAUSES. 
 
 45 
 
 has been improperly done. If the negative shows minute but 
 regular marks somewhat like the cells in a honey-comb, it is 
 caused by poor quality of gun cotton or an excess of ether. The 
 remedy is obvious. Should the plate be covered with fine ridges 
 running in the same direction, it is caused by the collodion not 
 being rocked properly until set. Should these ridges appear 
 high, curved and whitish after sensitizing the plate, they were 
 caused by the breath or a draft striking the plate while collo- 
 dionizing. Thick collodion and improper flowing or rocking will 
 also cause crapy lines like curtains. If the plate be not lowered 
 into the bath with a regular motion, each stoppage will be ap- 
 parent in the finished negative by a white line across the plate 
 where its course was arrested. If lowered too quickly, it will 
 cause streaks in the direction of the dippii^g. If lowered before 
 the collodion has set sufficiently, it will be spotted. This will 
 be more noticeable at the corner D than at any other. If the 
 film be allowed to dry too long before developing, the upper part 
 of the plate will have insensitive spots of a bluish color. If 
 removed from the bath too soon irregular greasy marks in the 
 shape of rivulets will be produced. Should a plate dipped into a 
 new bath be of a bluish cast instead of a rich creamy color, 
 iodize it more by putting in another collodionized plate over 
 night, as before directed. Should the temperature of the dark 
 room fall below seventy degrees, it may cause the same fault. 
 Should the glass be improperly cleaned, the film is liable to 
 tear and metallic silver will form between the glass and film. 
 Tearing may be caused by an excess of alcohol in the collodion 
 making it rotten, in which case the plate will have a rough ap- 
 pearance. 
 
 As has been noted throughout this and the preceding chap- 
 ters, the bath is the chief source of trouble, yet with ordinary 
 care one will last for years with but little correction. It has 
 been estimated that a square foot of collodion will take about 
 30 grains nitrate of silver from the bath. An amount equal to 
 that taken out should be replaced every night in the form of 
 concentrated solution, so that the hydrometer will register the 
 proper degree. With the utmost care organic matter will event- 
 ually so accumulate as to cause fog, pin holes, spots and streaks. 
 Boil the bath down to about half its volume in a porcelain evap- 
 orating dish to expel the alcohol, as before directed. Neutral- 
 
46 
 
 DEFECTIVE NEGATIVES. 
 
 ize the acid by adding concentrated water ammonia until red 
 litmus paper is turned blue by it, and expose in a large, white 
 glass bottle to the rays of the sun for at least two or three days, 
 in the meantime the duplicate bath should be used. Before 
 the second one commences to fail, the bath which has been 
 sunning should be diluted with water so as to register forty de- 
 grees on the hydrometer. It can then be filtered back into the 
 bath holder and acidulated with nitric acid C. P., when it will 
 work as well as new. Another way is to place the bath in a 
 bottle and add a solution of one dram permanganate of potash 
 in six ounces distilled water, a few drops at a time under con- 
 stant stirring, until the bath remains pinkish, it is then well 
 shaken and set in the sun until clear. This procedure is excel- 
 lent for a bath which is only slightly disordered. When in very 
 bad shape, it is recommended to pour the bath into a large 
 evaporating dish and apply heat. The water will gradually 
 evaporate, leaving grayish crusts on the bottom and sides of 
 the dish. Carefully increase the heat until these crusts melt 
 into a clear, oily liquid free from bubbles. Allow this liquid 
 nitrate of silver to cool and set, when it can be redissolved and 
 the solution made into a new bath. From constant use the bath 
 will also acquire an excess of iodide of silver, which will cause 
 the crystaline pin holes before alluded to. Take a large evap- 
 orating dish, and for every gallon of the bath put one quart of 
 distilled water into it. Pour the bath into this in a small stream. 
 Do not reverse the order of pouring, iodide of silver will be 
 thrown down in the form of a white precipitate. After filter- 
 ing, the bath is to be steamed and sunned, as before directed, 
 to remove the alcohol and organic impurities. New baths as 
 sold by dealers must be acidified, and also iodized before using. 
 
CHAPTER VI. 
 
 THE PRINT ON ZINC. 
 
 It is difficult to obtain zinc of a uniformly good quality. 
 The only satisfactory test is actual use. Ordinary sheet zinc 
 will not answer, as it contains too much lead, iron, sulphur and 
 carbon. Procure it from a reliable dealer. Cheap zinc is dear 
 at any price. If, after etching with a five per cent, solution of 
 nitric acid, the zinc shows streaks on both sides, like the grain 
 of wood, it has been improperly rolled. Small holes or black 
 lumps in relief show the presence of impurities. If a few small 
 scraps are dissolved in nitric acid CP., and if on addition of 
 sulphuric acid C. P. a strong white precipitate is formed, too 
 much lead is contained to fit it for etching. The side which 
 appears smoothest is not always the best. Make a test of a 
 sample cut from one sheet, and observing the characteristics of 
 the roll, further tests are not necessary with the same lot. For 
 printing purposes thick sheets are most desirable, but the ex- 
 pense of the metal and the extra trouble in polishing and hand- 
 Img have so decreased the thickness that one-sixteenth inch is 
 the standard generally adopted. This will weigh in the neigh- 
 borhood of two and one-fourth pounds to the square foot. It is sel- 
 dom rolled exactly to gauge, butthese figures are close enough for 
 an estimate. One-fourteenth inch is often used for better grades 
 of work. Zinc generally comes in sheets sixteen by thirty-six 
 inches, and is cut into smaller pieces according to size of work. 
 One-third of a sheet (twelve by sixteen inches) is the size 
 generally selected, but the etcher should always have on hand 
 polished pieces of every size from five by six inches to one-half 
 sheet. For cutting the zinc, select a table from thirty to thirty- 
 two inches in height. On the front edge nail a strip of hard 
 wood or brass one-fourth of an inch thick so that the end will 
 be eighteen inches from the end of the table. This strip is 
 
48 
 
 THE PRINT ON ZINC. 
 
 designated by A in Fig. 14. Nail the corresponding strip B 
 parallel with it and seventeen inches back of the front. Lay 
 
 Fig;. 14. 
 
 the sheet of zinc C between the strips, and the straight edge D 
 upon it and against the ends of the strips. A piece of long 
 primer or pica rule will make a good straight-edge. Grasp the 
 zinc hook, Fig. 15, in the right hand and, holding down the 
 straight-edge and the zinc with the left, set its point at E, about 
 half an inch from the further edge of the zinc. Now draw it 
 towards you, guiding it by the straight-edge with a light pres- 
 sure, so as to cut out a triangular strip of metal. Repeat this 
 operation several times until an appreciable groove has been 
 cut in the zinc, then remove the straight-edge and, applying the 
 pressure of the left hand to the end above the point, follow the 
 groove already formed. When about two-thirds through, the 
 zinc must be given a half turn, so that the half inch between 
 E and the outside edge can be cut. When the sheet has been 
 
 Fig. 15- 
 
 cut three-fourths through it may be removed to the edge of the 
 table, when the parts can easily be separated by bending two 
 or three times. 
 
 Some etchers use a saw, but this will raise a burr and is 
 liable to bend the sheet. The edges are now to be rounded 
 with a file so that there will be no danger of cutting the fingers 
 while handling, if the sheet is not perfectly flat, lay it on a 
 straightening block (an old press bed will answer nicely) and 
 straighten it with a mallet and planer. A hard wood block two 
 by three by two inches can be substituted for the latter. For 
 polishing, a tray should be mounted on legs, as illustrated in 
 
THE PRINT ON ZINC. 
 
 49 
 
 Fig. i6, so as to slant at an angle of about 30 degrees. Twenty 
 by twenty-four inches is a good size. The bottom edge should 
 be about thirty inches from the floor, so that the polisher can 
 bring his weight into play. Preferably, it is lined with zinc or 
 made water proof in some other way. On the bottom lay a 
 
 Fig. 16. 
 
 pad of three or four thicknesses of canton flannel, and fasten it 
 with tacks so that it will not move. This will prevent the zinc 
 from slipping under pressure. The bottom right hand corner 
 should be provided with a hole, and be somewhat lower than 
 the other corners, so that all the water will run to it. Fasten 
 a piece of heavy packing twine in this hole so that the drippings 
 will run along the twine into the bucket below the bench. Lay 
 the zinc upon the pad, file a piece of pumice stone so that it will 
 present a flat surface one or two inches square, dip it in the 
 water and rub vigorously in one direction only— to and from you. 
 Always lay the zinc so that the lines of rubbing will conform 
 with the direction in which the zinc was rolled. Select pumice 
 stone of the fmest quality and remove bits which break from 
 the lump, otherwise you are liable to make deep scratches 
 which will be difficult to remove. At first the oxide or grease 
 on the outside of the zinc will repel the water, but in a few 
 moments the pumice stone will take hold over the entire surface. 
 When the scale has been thoroughly removed, which can be 
 
50 
 
 THE PRINT ON ZINC. 
 
 easily noticed by the zinc assuming a bright, metallic appearance, 
 wash it off by pouring water upon it. If there are any serious 
 imperfections caused by rolling, set it aside. If, however, there 
 are only small holes and streaks here and there, wipe the plate 
 dry. Now, holding it in the left hand, grasp the callipers 
 (Fig. 17) in the right, pass the upper point immediately around 
 
 Fig. 17. 
 
 the outlines of the defective spot, but not in contact with the 
 zinc, pressing the lower point against the back of the plate so 
 that it will leave a mark. On turning the sheet upside down 
 the location of the defective , spot will be at once apparent. 
 When all the spots are located, lay the sheet upside down on 
 the straightening block and with a punch and hammer, or pre- 
 ferably a smasher hammer. Fig. 18, tap within the outlines of 
 
 Fig. 18. 
 
 the mark so as to bulge the zinc slightly on the other side. 
 When all the spots have been beaten up, return to the polish- 
 ing bench and rub again with pumice stone, removing the lumps. 
 This will cause the holes to disappear unless they are very deep, 
 in which case the operation must be repeated. Next take a 
 piece of Scotch stone about the size of your fist and file a small 
 flat surface upon it. Polish in the same direction as before," 
 until the scratches made by the pumice stone have been re- 
 moved. Be careful to clean the zinc and pad thoroughly, and to 
 use fresh water in polishing, as a small bit of pumice stone may 
 make a serious scratch when the work is nearly finished. Do 
 not use more water than sufficient to allow easy movement of 
 the Scotch stone. Wash the surface with clean water from 
 time to time. Should more holes make their appearance, locate 
 them with the callipers and beat out as before directed, 'when 
 the surface appears smooth it may be placed in an etching bath 
 
THE PRINT ON ZINC. 
 
 51 
 
 composed of sixteen ounces of water and one ounce of nitric acid 
 38°, and etched from five to ten minutes, the surface being mean- 
 while brushed with an etching brush. Provided the zinc is of a 
 good quahty, this will smooth it, and at the same time remove 
 the top layer of zinc, which is generally not as good as that 
 below it. Remove the plate from the bath, wash thoroughly 
 and again polish with Scotch stone. Many photo-engravers do 
 not etch at all, but proceed directly from the Scotch stone to 
 the final polish. Others use a zinc scraper. Fig. 
 19, laying the plate on a level surface and ap- 
 plying pressure with both hands in the same 
 manner in which the zinc hook is used, and 
 scraping in parallel lines until the outer layer 
 is removed. This is a most excellent method, 
 and when followed, the rubbing with pumice 
 and the subsequent etch may both be omitted. 
 When dull, the edges of the scraper can be 
 sharpened by rubbing them on a piece of emery 
 cloth stretched over a block of wood. Ordinary 
 
 charcoal will not answer for polishing zinc, as 
 
 it makes deep scratches. That sold for this 
 
 purpose by photo-engraving supply houses 
 
 should be obtained. It usually comes in pieces 
 
 about three by five by one and one-half inches. 
 
 Cut each block length-wise into two pieces. 
 
 This will make the block of convenient size. 
 
 Dip it into water and polish carefully in the 
 
 same direction as before, until the fine scratches 
 
 made by the Scotch stone have been entirely 
 
 ground away. Use the end of the block first, 
 
 and the grain side for finishing. Some etchers 
 
 now grind into fine powder the finest willow 
 
 charcoal, such as used by artists, mix it into 
 
 a paste with olive oil, and give a final polish, 
 
 pressing it on with a wooden block. Others buff the zinc and 
 
 polish with rouge. Large establishments use leather buffs, 
 
 coated with emery powder of various grades, to remove the 
 
 outer coating; and give a final polish with whiting or rouge in 
 
 the same manner. The fineness of the work depends greatly 
 
 upon the finish of the surface, and this work should not be en- 
 
52 
 
 THE PRINT ON ZINC. 
 
 trusted to a boy, as it requires considerable strength, skill and 
 experience. Experimenters will do well to purchase their zinc 
 ready polished, and many larger establishments pursue this 
 course. Etchers differ as to the desirability of graining the 
 p. ate before sensitizing, some maintaining that it spoils the sur- 
 face, while others claim this operation should never be omitted 
 for fine work. A^ake a bath of one quart of water, one dram 
 of nitric acid and one ounce of saturated solution of alum, and 
 place it in a rubber tray. Select a piece of zinc a little larger 
 than the job you wish to engrave, and lay it face uppermost in 
 this solution, in four or five minutes it will become gray and 
 acquire a very fine tooth or grain. Wash it carefully and, 
 while wet, take it into the dark room. Never allow the plate 
 to dry before pouring on the sensitizing solution. The water 
 should flow over evenly. Should it be repelled by any part of 
 the plate, it is caused by grease, which must be washed off' 
 before the albumen solution is poured on. Avoid touching the 
 surface of the plate with the fingers. Another way to clean the 
 plate is to pour a small quantity of aqua ammonia upon it and 
 rub over the surface with a tuft of absorbant cotton. To pre- 
 pare the sensitizing solution, take the white of an egg, and after 
 removing the germ, beat to a froth. Then add eighteen grains 
 bichromate of ammonia dissolved in eight ounces of distilled 
 water, and beat again; some etchers add a few drops of cone, 
 water ammonia. Now filter through a wad of absorbent cotton 
 lightly pressed into the neck of a funnel, it is best to support 
 the funnel on a funnel stand, and filter into a wide mouthed 
 bottle. Do not allow the solution to drip into the bottle, but 
 let it run down the sides, otherwise it will be full of froth and 
 air bubbles. The amount of albumen contained in an egg varies 
 with its size, but the above proportions are close enough for 
 practical use. Where fresh eggs are not obtainable, dry egg 
 albumen (half an ounce for the quantity above specified) may 
 be used, but it is more expensive and less satisfactory. After 
 a few hours the rest of the solution is ready for use, but as it 
 rapidly deteriorates, something easily discernable by the odor, 
 it should be freshly prepared every few days. A larger propor- 
 tion of bichromate of ammonia shortens the time of exposure, 
 but limits the period of exposure and heightens the chance of 
 having the print under or over-exposed. 
 
THE PRINT ON ZINC. 
 
 53 
 
 While the plate is still wet take it to dark room No. 2, hold 
 it by the lower left hand corner and pour the sensitizing solu- 
 tion on the upper right hand corner so that it will flow entirely 
 over the plate. Pour on a little more than is necessary to cover 
 the plate, allowing the surplus to run to waste. Repeat the 
 pouring several times, so that the solution will be full strength, 
 undiluted by the water which was on the plate. If poured too 
 rapidly, or if the mouth of the bottle is held too far from the 
 plate, air bubbles will surely result. See that the solution is 
 fresh, perfectly clear, and free from bubbles or froth. Should 
 any bubbles be formed by accident, pour on more solution until 
 they are washed away, otherwise when the print is developed 
 a white spot will result. Slant the plate at an angle of ten or 
 fifteen degrees, so that the surplus solution will drain towards 
 
 Fig;. 20. 
 
 one end, and hold it over an oil or gas stove to dry. Do not 
 use a lamp, as you are liable to smut the plate and break the 
 chimney. Be careful that the plate always slants in the same 
 direction, so that the surplus sensitizer does not run back over 
 the dried part. As it forms at the lower edge remove it with a 
 bit of blotting paper. Avoid heating the plate too much, or the 
 albumen will be cooked and the coating rendered insensitive to 
 light. For this reason it is best to hold the plate in your hands, 
 as any heat that can be borne by the fingers is safe. The plate 
 should be allowed to dry gradually from the upper end. in the 
 meantime the printing frame must be prepared. Many engrav- 
 ers use a modification of the photographer's silver printing 
 frame with heavy cross bars containing screws instead of 
 
THE PRINT ON ZINC. 
 
 springs. The kind illustrated in Figs. 20 and 21 is preferable, 
 inasmuch as the strain can be much more evenly distributed, 
 and the front will not be pushed out by repeated pressure. 
 The glass should be perfectly flat, smooth and transparent. For 
 small frames, three-quarters of an inch thick is amply sufficient. 
 For larger ones, one inch may be used. Take the frame apart and 
 carefully clean the plate glass. Replace it in the frame, and 
 should it fit loosely, fasten it with wooden wedges. Lay the 
 frame upside down, as in the illustrations, place the stripping 
 
 glass to which the film is attached and the sensitized zinc face 
 to face, and lay them glass side down on the center of the print- 
 ing frame glass. Before so doing carefully dust both sides with 
 a fine camel hair duster, as the least grain of foreign matter 
 will break the negative or plate glass when pressure is applied 
 to the screws. Lay the backing board upon the zinc and slide 
 the screw plate in above it. Be careful not to move the zinc 
 after it has been placed in contact with the negative. Now 
 turn the screws until you feel resistance. Do not bring any 
 one home, but gradually tighten them until they offer a mod- 
 erate amount of resistance. Beginners are apt to press too hard, 
 
THE PRINT ON ZINC. 
 
 55 
 
 cracking the negative or even the heavy glass. Do not tighten 
 the screws which are beyond the confines of the zinc. Now 
 expose the plate to the light. This can best be done by resting 
 the frame on a stand constructed for the purpose, and which 
 can be set at various angles. If sunlight is chosen, a shelf 
 should be constructed to extend from the window frame. In 
 direct sunlight the exposure will vary from two to eight minutes; 
 in diffused or electric light, from six to thirty minutes. Only 
 experience will enable the operator to time the print correctly. 
 Beginners had best divide the plate into four parts. After a 
 short exposure cover one-quarter with some opaque material, 
 then an additional quarter, and finally the third quarter. By 
 keeping track of the time each space was exposed and noting 
 the results upon development, the proper period can easily be 
 ascertained. 
 
 In the meantime, in the dark room preparations should 
 have been made for rolling up. For this an old lithographer's 
 tint roller which has been carefully handled is the best. It 
 should be perfectly smooth and free from lumps and indenta- 
 tions. Such rollers can seldom be purchased, and are almost 
 invaluable. Lithographers' rollers are made by fixing several 
 layers of flannel cloth to a wooden core and covering the out- 
 side with calf skin, the core being allowed to extend so as to 
 form handles. For smooth rollers the hair side is on the out- 
 side. If carefully made the seam is imperceptible to the touch, 
 and almost invisible. From use the skin gradually becomes 
 saturated with ink and the surface glazed. If carefully handled, 
 not only will the seam become invisible but the surface will be 
 free from holes and lumps, and the roller will acquire an elas- 
 ticity which it is impossible to impart by any other means. If 
 you cannot obtain an old roller in good condition, you can pur- 
 chase one prepared or prepare it yourself. Put a little castor oil 
 upon the inkslab and roll up the unprepared roller until the 
 leather and flannel are saturated with it. Avoid an excess: you 
 mist not be able to squeeze out oil by pressing on it. Let the 
 roler rest for a few hours, then pour a little lithographers' mid- 
 dle varnish (No. 2) upon the slab, and roll up until the leather 
 wil absorb no more. Do not put more varnish on the stone 
 until the first lot is entirely absorbed. Constantly change the 
 diiection of rolling, so that the varnish will be evenly dis- 
 
56 
 
 THE PRINT OX ZINC. 
 
 tributed. When the roller will absorb no more, lay it aside for 
 three or four hours, then repeat the operation. Do not leave 
 any varnish on the outside of the roller, but roll up until it is 
 entirely absorbed. This operation must be repeated once or 
 twice a day for two or three weeks. When the roller will not 
 take up any more varnish, scrape off the excess lengthwise 
 with a blunt knife (the back of an old case knife will answer 
 very nicely), being careful not to cut the leather. Lay it aside 
 for four or five days and again roll up with heavy varnish 
 (No. 3). After removing the excess of varnish the roller is 
 ready for use. Middle varnish must be perfectly clear and 
 transparent, and when a small portion is lifted from the mass it 
 must run out into threads two or three inches long. When 
 rubbed between the fingers it must make a distinct crackling 
 noise. Heavy varnish is almost as thick as gum, and but a 
 small portion should be spread at a time, hi cold weather the 
 slab may be warmed. During the operation of rolling up, and 
 afterwards, both slab and roller must be preserved from the 
 dust, it is best to make a low wooden box to cover the slab, 
 and on it rest a wooden support which will hold up the handles 
 of the roller and prevent its surface from touching the slab. 
 Still a better way for preserving the roller is to purchase a tin 
 roller cover made for the purpose. Handle covers made of heavy 
 leather will greatly assist in rolling up. in place of a litho- 
 graphic roller, many etchers use one of composition. It should 
 be cast of large diameter and be perfectly smooth. As usually 
 prepared for printers' use, they are too soft. Very little suc- 
 tion is required, but the surface should be straight from end to 
 end. Better have a roller cast of hard composition. An ordi- 
 nary one, on drying out to the proper hardness, generally 
 shrinks so unevenly that it rests on the ends, and the middle 
 does not touch the slab without undue pressure. Rubber rol- 
 lers are sometimes used for the purpose, but as they are much 
 more expensive than those of composition, they are not recom- 
 mended. Ink made for the purpose should be purchased. Some 
 grades of lithographers' transfer ink will answer, but often it 
 contains too much tallow, and the developed image will not have 
 enough strength to hold the etching powder or resist the acid. 
 As good ink can be purchased at a reasonable price, and the 
 beginner cannot make it properly without expensive apparatus, 
 
THE rh'/X T ON ZINC. 
 
 57 
 
 the formula will not be given. For the sake of convenience, 
 this ink will be referred to as etching ink No. i. Make sure 
 that the roller is perfectly clean. If it has acquired any dirt 
 from rolling up, scrape it off with a dull knife or rub with a rag; 
 dipped in turpentine. When thin ink is used for rolling up, it 
 will not hold the etching powder sufficiently to resist the acid. 
 As the thick ink is difficult to distribute, take a small quantity 
 of it, place it on a slab and rub it with the ink knife so as to 
 cover as much space as possible. At the side of the slab have 
 a bottle of rectified turpentine, through the cork of which a small 
 hole has been bored. Sprinkle a little of this over the ink and 
 roll up until it is distributed smoothly over the slab and the roller. 
 The least speck of dirt or undistributed ink may play havoc 
 with the print, if the proper amount of ink has been used the 
 slab will still be visible through it. As the rolling up proceeds 
 the turpentine will evaporate, and more must be added until 
 the distribution is perfect, but the plate should not be rolled up 
 until the turpentine has almost all evaporated. Lay a piece of 
 zinc with the exposed side upwards upon the slab and roll 
 briskly until the plate is coated evenly. Turn the zinc from 
 time to time so that the direction of rolling will be changed. If 
 properly applied, the coating will be of a perfectly even shade, 
 and so thin that the yellowish color of the bichromatized zinc 
 can be plainly discerned through it. Beginners usually make 
 this coating too thick. The plate is now taken from the dark 
 room and laid face upwards in a shallow rubber tray, and 
 enough clean, cool water is added to barely cover its surface. 
 Allow it to remain for about five minutes, or until the water 
 has penetrated the ink, then take a 'pinch of clean absorbent 
 cotton, and rub it against the surface with an easy circular 
 motion. Do not apply too much pressure, otherwise you will 
 smudge the print. Commence on the margin, working towards 
 the center. If the exposure was timed correctly the ink can be 
 removed with little difficulty, and the engraving will appear in 
 the form of black lines against a bright background. Should 
 any part of the image be hard to develop, let it alone while you 
 are rubbing the balance and come back to it afterwards. Do 
 not rub longer than is necessary to bring out the clear image. 
 If the plate has been over-exposed it will be difficult to remove 
 the ink from the white spaces, requiring so much pressure that 
 
dS 
 
 THE PRINT ON ZINC. 
 
 the lines will be smudged or obliterated, if under-exposed the 
 image will rub off with the rest of the ink. The addition of a 
 few drops of ammonia or saturated solution of bichromate of 
 ammonia to the tray will often aid in the development of a 
 plate which has been only slightly over-exposed. Should part 
 of the plate develop and the balance fail to do so, it was prob- 
 ably caused by an uneven negative, or uneven distribution of 
 the sensitizing solution caused by not flowing it as above 
 directed. Heating the plate so as to cook the albumen will 
 have the same effect, as will also imperfect union between the 
 
 Fig 22. 
 
 zinc and the negative, caused by insufficient pressure on the 
 screws or inequalities in the surfact? of the zinc or stripping 
 glass. These defects can generally be located with little trouble. 
 Should the lines be heavier than those in the negative, it is 
 probably caused by the use of too much ink or undue pressure 
 in development. 
 
 Wash the plate thoroughly in running water, blot off the 
 water with a damp cloth and heat over a gas stove to a degree 
 not hoter than the hand can comfortably bear. Lay the plate face 
 upwards on the retoucher's table, take a little of the No. i etching 
 ink, place it on a saucer and, thinning it with rectified turpentine. 
 
THE PRINT ON ZINC. 
 
 59 
 
 paint the borders within a quarter of an inch of the outlines of the 
 cut, using camel hair brushes of various sizes, j if the plate is to be 
 finished by routing, or with the jig saw, paint the large white 
 spaces in the body of the cut also, as this willisave acid. Fig. 22 
 shows a proof of an engraving THE 
 as painted in, and Fig. 23, the f 
 same cut after routing. Now place 
 the zinc beneath the bridge, as 
 illustrated in Fig. 24, and examine 
 the print with a strong magnify- 
 ing glass. If any lines are mis- 
 sing they must be painted in with 
 No. I etching ink thinned with 
 turpentine, applied with fine art- 
 ists' camel hair brushes, of which 
 there should be several. Should Fig. 23. 
 
 the lines be too wide, or should there be any black spots, they 
 must be scraped away. Lithographers' needles, the points of 
 
 Fig. 24. 
 
 which are ground to various shapes, are best adapted to this 
 purpose. The plate is now ready for powdering up, as directed 
 in the next chapter. 
 
 PRINTING WITHOUT A FRAME. 
 
 Another method of making the print dispenses entirely 
 with the frame. Numerous experimenters have succeeded in 
 doing this, but the following, originated by Mr. Chas. Chetham 
 in 1884, is by far the best. The advantages are: All danger 
 of breaking either the stripping glasses or printing frame glass 
 is avoided; it is easier to handle the plate than the heavy print- 
 ing frame; where the zinc surface is not perfectly plane, the 
 contact is better; the exposure is shorter; and' the size of the 
 zinc is not limited to that of the printing frame, as any number 
 of films may be attached to a sheet and printed at the same 
 time. 
 
 Both stripping solutions should be applied more thickly 
 than is necessary when stripping glasses are used, so that the 
 
60 
 
 THE PRINT ON ZINC. 
 
 film will be heavier. It is sometimes necessary to add a little 
 more castor oil to the stripping collodion than directed in the 
 formula given in the last chapter, but this can be arrived at by 
 trial. Strip the film as if for mounting on glass and dry it be- 
 tween blotters. 
 
 Coat the zinc in the usual manner with albumen sensitiz- 
 ing solution, and when it is dry pour a few drops of castor oil 
 upon it, distributing it evenly with a clean composition roller. 
 Lay the film upon the surface, commencing with one end and 
 gradually lowering the rest as when fastening it to the stripping 
 glass, and smooth it down with the finger tips. Air bubbles 
 may be dispelled by piercing their centers with a fine needle. 
 After exposure the plate is rubbed over lightly with a wad of 
 absorbent cotton. The small amount of oil left upon the plate 
 does no harm, and is really a benefit, as it assists the distribu- 
 tion when rolling up. For fine work, such as half tone, always 
 use the printing frame. Beginners had best use it for coarse 
 jobs as well, until they thoroughly master the other branches 
 of the business. 
 
CHAPTER VII. 
 
 Powdering and Etching. 
 
 Dragon's blood is almost universally used for powdering 
 the plate. It is a resinous gum, the exudation of several tropi- 
 cal trees. There are so many varieties of the pure gum, and 
 there is so much adulteration that it should be purchased only 
 from a photo-engraver's supply house. The best is of a deep 
 red color, ground to an impalpable powder. It makes an ex- 
 cellent resistance against acids and is not liable to stick to the 
 spaces between the lines. The only objection against it is its 
 tendency to make the surface rough when melted, and its ex- 
 treme brittleness. With proper manipulation these faults will 
 give little trouble, and for the finest work they can be corrected 
 by the addition of other ingredients. As these will vary, both 
 as to quantity and kind, according to the qualities of the drag- 
 on's blood, it will pay far better to purchase than to experi- 
 ment yourself. At least one pound of powder should be placed 
 at the bottom of the powdering box. This is made of wood, 
 about three inches in depth and several inches larger than the 
 largest plate which it is intended to etch. In one end about an 
 inch from the top is a cross strip. A hinged cover is thrown 
 over it when not in use, so as to prevent dust from being mixed 
 with the etching powder. Lay the retouched plate in the box, 
 and with the flat powdering brush (one of fitch hair, and two 
 and one-half inches wide, is best) heap a quantity of powder upon 
 it. With the same brush distribute the powder thoroughly, 
 allowing time for the ink to absorb as much as possible. Brush 
 away the surplus powder with the same brush, then take a 
 clean, heavy, flat camel hair brush two and one-half inches 
 wide, used for this purpose only, and thoroughly brush again. 
 Do not apply enough pressure to injure the lines. When the 
 drawing is of a reddish brown color against a perfectly clean 
 background of polished metal, it is ready for melting. For heat- 
 
62 
 
 POWDERING AND ETCHING. 
 
 ing the plate, a covered oven with several rows of burners will 
 be found most satisfactory. One similar in construction to a 
 gas griddle, but having wires instead of a solid slab over the 
 burners, is recommended. For small work but one or two rows 
 need be lighted. Beginners can use an ordinary Bunsen burner, 
 moving the plate so as to distribute the heat. For holding 
 
 the plate during the melting on, a pair of wide nosed pliers will 
 be found most satisfactory. Hold the plate by one of its edges 
 and lay it on the wires. As soon as the powder melts and com- 
 bines with the ink, which is at once noticeable by its becoming 
 a bright, deep brown instead of the dull red, remove it from the 
 oven and lay it on the stone or metal slab. This should be 
 perfectly flat and be placed at the side of the oven. Should 
 the heat be continued too long the lines will become heavier. 
 
POWDERING AND ETCHING. 
 
 63 
 
 the coating brittle and the zinc warped and twisted. Paint the 
 back and edges of the plate with asphaltum varnish to prevent 
 the acid from attacking the zinc in these parts. Heat the plate 
 slightly to expel the turpentine from the varnish. When cool, 
 it will be ready for etching. 
 
 The form of etching tub shown in Fig. 25 is most desirable. 
 For ordinary work -twenty by twenty-four inches is large enough. 
 It should be acid proof and of well seasoned lumber. Some etchers 
 use chemically pure nitric acid for the first etch, but the majority 
 take the commercial grade, 38 degrees. Pour about one quart 
 of water into the tub and add three quarters of an ounce acid. 
 Rock the tub several times so as to mix well, then lay the plate 
 in the center. Rock slowly so that the acid will run over the 
 plate in even waves. \\\ a short time the surface will become 
 covered with a grayish deposit. This is removed by gently 
 brushing with a camel hair or bristle brush used for this pur- 
 pose onFy. The rocking need not be interrupted for brushing, 
 neither should the brushing be continuous. Ordinary brushes 
 set in glue will last but a short time, the acid rapidly destroy- 
 ing them. Rubber bound brushes sold for the purpose are the 
 best, but those bound in tin can be made to answer by giving 
 them several coats of asphaltum. Watch the zinc carefully, 
 examining it from time to time under the retouching glass. 
 Should any of the finer lines show signs of giving way, or 
 should the zinc appear to show through the coating, the plate 
 must be taken out of the tub, thoroughly washed, and the defec- 
 tive parts touched up, or the entire plate gummed, inked, dried 
 and re-powdered, as directed in the next chapter. From time 
 to time the plate should be given a quarter turn, so as to change 
 the direction of the flow. The depth of the first etch will vary 
 according to the class of the work. In crayon or fine line work 
 the relief must not be more than the thickness of writing paper. 
 For ordinary work the etching may be continued until the relief 
 is that of a thin card-board. This will usually take from eight 
 to ten minutes, and will be apparent by a bright rim around 
 the lines. The thumb nail is usually applied as a test. Should 
 the shoulder have progressed enough to engage the nail the 
 etching must be stopped. With a very little experience the 
 beginn'er can judge when the proper relief has been attained. 
 When it is judged that the first etch has proceeded far enough, 
 
64 
 
 POWDERING AND ETCHING. 
 
 take the plate from the tub and wash it thoroughly. Remove 
 the water by blotting off with a damp rag and then warm over 
 the oven. Now examine the plate carefully. Should any of 
 the lines be weak or the coating wholly removed they must be 
 touched up with a fine camel hair brush dipped in a mixture of 
 No. I etching ink and turpentine, if used thinner than the 
 consistency of cream, the ink will not be strong enough to hold 
 the powder or resist the acid. As it is very difficult to make 
 fine lines with such heavy ink, great care must be exercised at 
 this point, otherwise the lines will be too heavy in the finished 
 cut. Place the plate back into the powdering box and, cover- 
 ing it thoroughly with powder, rest it against the rail as before 
 directed. Hold the plate by the lower left hand corner, resting 
 the top against the strip in the powdering box, and brush in 
 lines parallel with the top and bottom, from right to left only, 
 lifting the brush on the return stroke. When the powder has 
 been removed from the surface of the plate, use the softer brush 
 with the same motion. When all the powder has been brushed 
 out of the white spaces, bring the plate to the oven and heat 
 as before, just sufficiently to melt the powder. Place it on the 
 slab, and when it has cooled grasp it by the lower right hand 
 corner and, resting the left edge against the rail, bRish the 
 powder from the top to the bottom of the plate, again taking 
 the precaution to lift the brush on the return trip. Repeat the 
 melting and cooling, then put it back into the powdering box. 
 This time hold it by the upper right hand corner with the bot- 
 tom edge resting against the rail and brush the powder from right 
 to left. Melt on the powder and repeat the operation, holding 
 the plate by the upper left hand corner, resting the right edge 
 on the rail, and brushing from bottom to top of the design. 
 Heat again, when the shoulder of the first etch will be found 
 thoroughly covered with melted etching powder. Always brush 
 against the plate, not away from it, otherwise you will dislodge 
 the powder from the crevices. While cooling for the last time, 
 add a little acid to the etching tub and rock so as to distribute 
 it. As the first etch has taken out a quantity, varying with 
 the amount of zinc dissolved, the tongue is the best standard. 
 Add sufficient to make it taste the strength of vinegar— from 
 one to two ounces. The second etch should be continued about 
 five or ten minutes, but the acid being stronger, the amount of 
 
POWDERING AND ETCHING. 60 
 
 relief obtained will be greater. No standard can be given. The 
 operator must use his judgment. At the beginning he had best 
 err in making it too short th^n too long. The beginner may 
 clean a portion of zinc at the edge where there is no design, so 
 that he can make the thumb nail test before alluded to. Re- 
 move the plate and examine it carefully. If the job is a fine 
 one, some portions will by this time have sufficient relief. 
 Should the powdering fail to fill the counters, such parts must 
 be painted over with the mixture of etching ink No. i and tur- 
 pentine, otherwise the lines will be undercut or lost. The 
 plate is then to be powdered and melted on four times exactly 
 as before, when it is ready for the third etch. The quantity 
 of acid and duration of the etch must again be left to the judg- 
 ment of the etcher. Usually about the same amount as in the 
 second etch is taken. Should the progress be too slow, a little 
 more can be added from time to time as the etch progresses. 
 It should always be borne in mind that too little will do no 
 further harm than prolong the work, while too much will in- 
 evitably spoil the cut. If the work covers a plate fully, i. e., 
 if the lines are close together, three etches will be sufficient. 
 Very open work, such as diagrams, etc., will require as many 
 as six or eight etches, the same precautions being taken as 
 before. Unless perfectly straight, the plate is liable to float 
 when a wave of acid strikes it. This is particularly true of 
 small ones. It can be avoided by bending the plate slightly 
 so that the back is concave, by rocking a little slower, hold- 
 ing the plate down with the fingers, or by fastening it to the 
 box with a thumb tack. Nitric acid, even in the diluted state, 
 will turn the skin and finger nails yellow. Even with the 
 utmost care the etcher cannot altogether do away with this, 
 but' the greater part can be avoided by covering the hand. 
 Rubber gloves are awkward, but the finger tips sold for the 
 purpose will not seriously inconvenience him. From constant 
 handling with pliers while hot, the asphaltum on the back of 
 the plate will be worn off in places, so that the acid will attack 
 it. Small holes, particularly on the edges, will do the plate no 
 harm. Black spots of greater or less extent in the white spaces 
 are generally caused by insufficient brushing or dusting. If 
 they are small and appear after the second powdering, they 
 need cause no alarm, as the strong acid of the second etch will 
 
66 
 
 POWDERING AND ETCHING. 
 
 remove them. If, however, they are large, they must be care- 
 fully scraped off before etching.^ Should the zinc be of a poor 
 quality, so that it has projections and holes, it will cause the 
 same trouble. The only remedy is to scrape them off when- 
 ever they appear. Should any of the lines be lost, particularly 
 the finer and isolated ones, the fault probably lies in using too 
 strong acid, continuing the etch for too long a period, or heat- 
 ing the plate so much as to burn the coating. Other causes 
 are, brushing the powder too long, or away from instead of 
 against the plate, and ink or etching powder which will not 
 resist the acid. These faults, though much more apparent in 
 the finer lines, will also be noticeable in the coarser ones. 
 Irregularities at the bottom of the plate are generally caused 
 by poor zinc or insufficient and uneven brushing during the 
 etch. 
 
 Lay the plate on the etcher's oven and heat it sufficiently 
 to melt the coating. Take it to the sink and pour a little ordi- 
 nary turpentine upon it. While still hot, brush rapidly until 
 the coating is dissolved away. It can then be given a final clean- 
 ing with lye or benzine, and polished dry with hot sawdust. 
 The sawdust should not be allowed to enter the sink, otherwise 
 • wp 5u/RrAC€ ^^'^ choke the drain, if the etching 
 
 srcmoWcH ' H ^as been properly done, both as re- 
 
 m/^ cm - r j gards time and strength of acid, and 
 
 BorroM 5uRf-AC£ ' ' if the proper amount of powder was 
 
 Fig- 26. allowed to remain upon it, the cross 
 
 section of two lines strongly magnified would appear somewhat 
 like Fig. 26, or like Fig. 27, each shoulder recording the limits 
 of an etch, in all probability, however, it will appear more 
 like Fig. 28. Should any of the lines be badly undercut, Jike 
 Fig. 29, so that the base is little wider than the top, it will be 
 
 Fig. 27. Fig. 28. Fig. 29. 
 
 impossible to save the cut: it had best be thrown away and a 
 new one made. Should it appear like Fig. 28, take the plate 
 into the dark room No. 2 and spread a little No. 2 etching ink 
 upon the slab. This is stiffer and less greasy than the No. i. 
 
POWDERING AND ETCHING. 
 
 67 
 
 Carefully distribute, and roll it up with the addition of a little 
 turpentine, but put a little more on the roller and slab than 
 before directed. The No. i etching ink will answer, but is not 
 quite as good. See that the plate is perfectly clean, warm it 
 slightly and lay it on the slab. Roll over very lightly, so as 
 not to ink up the blank spaces or the sides of the lines. Allow 
 it to cool, then dust powder upon it. Melt it on, let it cool, 
 dust again, and repeat the operation once or twice more, or 
 until the ink will absorb no more powder. \n heating up, be 
 careful not to bring the plate to too high a temperature, other- 
 wise the mixture will run too far down the sides. If properly 
 done, only the top of the lines and part of the first shoulder 
 will be covered. Now place the plate in the etching tub again, 
 with fresh acid no stronger than that employed for the first 
 etch. Examine it from time to time with a magnifying glass, 
 and if the steps are not sufficiently reduced before there is 
 danger of undercutting the lines, remove the plate and repeat 
 the entire operation of inking and dusting, using more ink, or 
 heat so lhat the coating will run down further on the sides of 
 the lines. Clean the plate again, and if found right, clean the 
 back as well, when it is ready for the router. Beginners are 
 apt to leave too much powder on the plate when _ 
 powdering, so that a cross section of the lines will 
 appear like Fig. 30 when cleaned off for the first /! ' '''''"^ 
 time. This is not nearly so serious a fault as if 
 the lines were under-etched, since it can be cured hr. 30. 
 by rolling and powdering, as above directed, although in this 
 case it may take several additional finishing etches. Large 
 establishments run their etching tubs by power, using a separ- 
 ate countershaft for each tub, connecting with the main shaft 
 in the finishing room. If properly balanced one horse-power is 
 enough for many tubs. 
 
 ETCHING ON COPPER. 
 
 For the finer class of half-tone work, many etchers prefer 
 copper, it should be polished and prepared in the same man- 
 ner as zinc, but the weak acid used for the last named material 
 would have scarcely any effect upon it. Unless the coating is 
 unusually strong, concentrated acid would destroy it. For this 
 reason a saturated solution of perchloride of iron is generally 
 employed for the first etch, the plate being laid in a tray or 
 
68 
 
 POWDERING AND ETCHING. 
 
 suspended in a bath for ten or fifteen minutes. Unlike acid, 
 the saturated solution of this salt will not attack the metal as 
 much as one which has been diluted with water. Should even 
 the concentrated liquid act too strongly, it must be reduced by 
 allowing it to work upon a piece of scrap copper. After the 
 first etch, wash off the plate under the tap, using a soft brush. 
 It is then returned to the bath, the operations of etching and 
 washing being repeated until the requisite relief is obtained. 
 Nitric acid, two ounces to the quart, may be used for etching, 
 but though faster is liable to undercut the fine dots. 
 
CHAPTER VIII. 
 
 Gumming Up. 
 
 Another method of protecting the sides of the lines is that 
 of gumming and rolling up. The slab should be smooth, pre- 
 ferably of marble. A lithographic roller must be used for this 
 purpose : one of composition will not answer. One with rough 
 outside finish is best adapted to this purpose. They are gen- 
 erally termed "black," to distinguish them from the smooth or 
 tint' rollers, and should be prepared for use exactly in the 
 same manner as directed in Chapter VI. Etching ink No. i can 
 be made to answer, but one containing no fat, but instead, a 
 mixture of wax and resin, will give better results. To distin- 
 guish this from the rolling up ink, it will be called No. 2. Back 
 of the slab, have three shallow cups of glass or porcelain. Pro- 
 cure a fine velvet sponge of such size that when wet it will be 
 a little smaller than the fist. Beat it out thoroughly and leave 
 it over night in a mixture of one part hydrochloric acid and 
 thirty parts water. This will remove the last trace of lime. 
 Wash thoroughly, so as to remove all the acid. Put one ounce 
 gum arabic in a wide-mouthed bottle and add about four ounces 
 \Vater. Stir it occasionally, and at the end of two or three days 
 the gum will be thoroughly dissolved, forming a liquid of a 
 syrupy consistency. Should any part remain insoluble in cold 
 water, but simply swelled, the gum is adulterated. Strain the 
 gum through a piece of muslin, and to every one hundred parts 
 solution add three parts phosphoric acid. Stir thoroughly, and 
 should it contain any impurities, filter again. Pour a little of 
 this in the first cup, into the second place the clean sponge, and 
 into the third, pure water. After the first etch, dip the sponge 
 into the gum solution and rub lightly over the plate until it is 
 coated with an even layer of gum about the thickness of writ- 
 ing paper. The coating must be perfectly smooth, without 
 streaks or bubbles. The gum must now be dried. This can 
 be hastened by fanning : do not subject it to heat. Take a 
 
 69 
 
70 
 
 GUMMING UP. 
 
 little of the No. 2 etching ink and spread it on the surface of 
 the slab with the ink knife. Add a little rectified turpentine 
 and distribute it thoroughly. Lumps, however small, will make 
 spots in the plate. The coating should be considerably heavier 
 than for developing ; about as thick as is used when proofing. 
 Do not use more turpentine than necessary. When evenly 
 distributed, squeeze the gum which is left in the sponge back 
 into its cup, and dip the sponge into the cup containing water. 
 Squeeze the excess of water out, and rub lightly over the zinc 
 so as to remove the coating of gum from the surface of the lines, 
 being careful not to rub so hard as to remove it from the white 
 spaces. When the turpentine has evaporated, roll over the 
 wet plate, pressing evenly and very lightly. At first the ink 
 will not take readily, but with continued roiling the lines will 
 be covered with a smooth, even coating. Should the ink stick 
 to the white spaces, remove it by rubbing gently with the 
 sponge which now contains a very diluted solution of gum 
 arable. Should the roller become wet from the plate, wipe with 
 a clean rag and roll it out on the slab. When evenly coated, 
 take the plate to the sink and wash it under a rose tap, rubbing 
 very lightly with the sponge until all the gum is removed from 
 the surface. Do not rub hard, otherwise you will smear the 
 "ink. When thoroughly clean, blot off the surplus moisture with 
 a damp, clean rag, and dry with very gentle heat or a fan. 
 Now take the plate to the powdering box and dust thoroughly 
 until the ink will absorb no more. Be careful not to apply too 
 much pressure, otherwise the lines will spread. Heat the plate 
 sufficiently to make the powder combine with the ink. When 
 cool, should the coating be tacky instead of firm, repeat the 
 powdering and melting operations. If carefully performed, the 
 shoulder made by the first etch will be completely covered and 
 protected from the acid by the coating of ink and etching powder 
 running down the sides. It may then be etched as before. 
 After the second etch the same procedure may be followed, but 
 a little more pressure should be applied when rolling up, so as 
 to deposit some ink on the sides of the lines as well as on the 
 surface. In the hands of a skillful workman the gumming and 
 inking up will produce the finest results. It is, however, some- 
 what slower and much more difficult than powdering four times, 
 therefore many establishments do not use it at all. Some gum 
 
GUMMING UP. 
 
 71 
 
 up after the first etch only, using the powdering method for all 
 subsequent etches, while others gum up only when the drawing 
 appears weak. This last, however, seldom happens unless the 
 job is very delicate, the ink or etching powder of a poor,quality, 
 or so much heat is used in melting on as to make the coating 
 brittle. Cleanliness is of the highest importance. The ink 
 slab, sponges and cups should be covered when not in use, and 
 be removed some distance from the powdering box. The slab 
 should be cleaned often. Clean the roller every night by scrap- 
 ing lengthwise with the grain with a dull knife held slanting so 
 as not to cut the leather, and keep it in a tin roller cover while 
 not in use. If it is to be left unused for some time, rub its 
 surface with tallow, but be careful to remove all grease by 
 scraping before using again. The gum solution should be 
 freshly prepared with acid every morning, and not more should 
 be dissolved in water than will last two or three days. There 
 is another method of gumming up, in which the ink is applied 
 with a sponge instead of a roller. As this is more difficult, 
 and, except in the hands of an expert, gives less satisfactory 
 results, it will not be described. 
 
CHAPTER IX. 
 
 ROUTING AND FINISHING. 
 
 In an establishment of any considerable size, power machin- 
 ery is essential. The main shaft should be at least one and 
 eleven-sixteenth inches in diameter, and be attached to the 
 ceiling in a line about eight or ten feet behind the finishing 
 machinery, by hangers of at least twelve-inch drop. Self-oiling 
 hangers which require filling but once in three months are most 
 economical. The speed of the shaft will vary, according to 
 circumstances, from one hundred and fifty to two hundred 
 revolutions per minute. 
 
 There is great difference of opinion as to what speed the 
 spindle of the router should run. Some recommend as high as 
 15,000 revolutions per minute, but in practice it has been found 
 that the speed of from six to ten thousand revolutions per 
 minute is amply sufficient. In a router running at this last named 
 speed, the spindle pulley being two inches in diameter, and the 
 belt running six inches at each revolution, the latter will travel 
 five thousand feet, or almost a mile, per minute. Such speed 
 will soon tell on the belt and wearing parts of the machine, 
 even when of the best material, and a higher rate will increase 
 this wear in greater proportion than the additional speed. 
 Fig. 31 shows one of improved construction. The machine 
 should be placed in such position that a good light will be 
 thrown on the work. Should a sheet of zinc be warped by 
 over-heating during the etching operation, it must be straightened 
 and then clamped firmly to the bed of the router. The form 
 
 ^^^^ f 1(1 
 
 i-ig. 32. 
 
 of cutter shown in Fig. 32 is preferable. Most operators 
 
 prefer to grind the tools so the back will present a view shown 
 
 ■ ii, , _ in Fig. 33. This increases the efiiciency, enabling 
 
 ^^3^^^ the workman to do much more work in the given 
 
 r^ig- 33- time, but does not make quite so smooth a finish 
 
 as when the bottom edge is almost square. The cutter must 
 
 73 
 
74 
 
 ROUTING AND FINISHING. 
 
 be tightly fastened into the spindle. Pressing the foot on the 
 treadle will bring the cutter against the zinc, the depth of cut 
 being regulated by adjustment of the screw on the head. It 
 requires considerable experience to rout closely to the lines 
 without occasionally cutting into them. The cutters preferred 
 for general work are three-sixteenths and five-thirty-seconds 
 of an inch in diameter. After finishing with one of these tools, 
 many of the best photo-engravers remove it and substitute a 
 smaller one, one-eighth or one-sixteenth of an inch in diameter, 
 routing out such places as will not admit the larger tool. 
 
 Fife- 34- 
 
 Fig. 34 shows the fluted cutter generally employed for type 
 metal and wood. Always keep the cutter in good condition, 
 sharpening from the bottom edge only. Do not touch the side. 
 If properly done the routing will leave ample relief in every 
 part, and without any burs. Many photo-engravers give the 
 final or finishing etch after the routing, so as to remove the 
 sharp edges formed by the cutter and give the cut a smooth 
 and even appearance. Foot power routers are impracticable. 
 The high speed required for zinc, and the consequent exertion, 
 will shake the operator so much that the work must be done 
 very slowly, and fine work cannot be done at all. The begin- 
 ner who cannot afford power machinery had best send his work 
 to some electrotype foundry for routing and blocking, or etch it 
 down to proper depth. Still another way is to purchase a light 
 jig saw, not such as used by electrotypers, but the kind 
 generally employed for fret work, carrying a saw about one- 
 sixteenth of an inch in width, and saw completely around the 
 cut, leaving only enough room for the tacks. Large spaces in 
 the body of the engraving may be cut out in the same manner, 
 by first making a hole with a hand drill for the insertion of the 
 saw blade. Both of these procedures are, however, com- 
 paratively slow and unsatisfactory. After the plate has been 
 routed it is taken to the circular saw and the edges trimmed 
 away as much as possible, somewhat as shown by the dotted 
 lines in Fig. 35. The speed of the saw will of course depend 
 largely upon its diameter. For a seven to nine-inch saw, 3,000 
 revolutions per minute will be found about right. The same blade 
 
ROUTING AND FINISHING. 
 
 75 
 
 will not cut wood, metal or zinc equally well. The wood blade 
 would dull and stick in zinc, and the zinc blade would 
 heat and wedge fast in wood. The form known as hollow- 
 
 edges, will not do nearly so well), and occasionally trued by 
 raising the table until the edge of the saw barely projects, and 
 passing a small slip of oil or grindstone over the opening while 
 the saw is revolving. Different blades may be put on the 
 same saw mandrel, as required. A better way is to purchase 
 separate frames, or one having two spindles, as illustrated in 
 Fig. 36. Revolving the handle will make one saw descend and 
 the other rise in its place. Almost all cuts are mounted on 
 wood. Mahogany is preferable, but on account of its cost 
 cherry and birch are generally chosen. It will vary in thick- 
 ness according to the gauge of zinc, and should be perfectly flat 
 and even. Unless there is sufficient work to warrant the 
 purchase of a Daniel's planer, it is best to buy the wood planed 
 to the correct thickness. Be sure that it is dry and thoroughly 
 seasoned. Saw off a block about one-eighth of an inch larger 
 than the engraving. Small mounting blocks are generally made 
 in a single piece. When of considerable size, particularly when 
 there is no certainty that the wood will not warp, the main 
 piece is grooved like B, Fig. 37, and the side pieces A should 
 be tongued so as to fit into the mortises. There are special 
 machines made for this purpose, but the work can also be done 
 on the routing machine, Fig. 34. Another way is shown in 
 
 ground is much to be preferred, 
 although for wood an ordinary saw 
 
 >' \ here the hollow-ground blade is to be 
 )) I preferred, as it does not require so 
 ^ I much skill to keep it in order. For 
 j I wood, there should be three or four 
 ' teeth to the inch; for type metal, five 
 I I or six; for zinc, eight, and for copper, 
 ' eleven. The shape of the teeth will 
 I differ slightly according to the material. 
 ' It will pay to purchase the very best. 
 The saw should be sharpened when- 
 
 with teeth properly set will do. Even 
 
 ever dull with a three-square file 
 (the ordinary saw file, having blunt 
 
Fig. 36. 
 
ROUTING AND FINISHING. 
 
 77 
 
 Fig. 38. The main block has triangular grooves planed in the 
 sides. Inasmuch as the end strips do not receive the 
 
 B 
 
 B 
 
 B 
 
 Fig. 37. 
 
 tacks, they may be made of hard wood, such as oak. When 
 the blocks are very large, the center is often composed 
 of several sections, like B, Fig. 37, spaces being left be- 
 tween adjoining pieces to prevent warping. Still another 
 plan is to score the bottom of the cut with the saw, cutting 
 
 , half way through so as to divide 
 
 i 
 
 Fig-. 38- 
 
 it into a number of blocks two 
 J inches square. This reduces 
 the liability to warp, but is 
 objectionable for other reasons. 
 Remove the sharp corners from the zinc plate with the 
 file, lay it on a piece of hard wood, and with a hammer 
 and nail punch make small holes at frequent intervals, 
 as illustrated by X in Fig. 35- With the file remove 
 the burs formed at the bottom of the plate, and if the 
 zinc has been bent, straighten it carefully. Rest the wood 
 
 Fig. 39- 
 
 block on the finishing plate. Fig. 39, and lay the zinc upon it. 
 Place it somewhere near its position, drive in a single tack, and 
 then turn the zinc until the cut is square with the corner of the 
 
78 
 
 ROUTING AND FINISHING. 
 
 block, which rests'against the squaring device of the finishing 
 plate. Then fasten it down, when the other tacks may be 
 driven in. For mounting on wood, the wire nails should be 
 rather thick and have lar^e heads. Half and five-eighth inch 
 are the lengths general) / used, but in some places as long as 
 three-fourth inch are used. They should be driven home with 
 a nail punch. Where the space is too small for the head of 
 one of these nails, wire brads may be taken. If the cut be so 
 closely covered with lines as to afford no space for tacks, the 
 
 Fig. 40. 
 
 edge may be beveled in the shoot board, Fig. 40, by using a 
 special beveling plane. It can be fastened to the block by 
 driving the tacks diagonally ^ 
 into it, as in Fig. 41. This 
 necessitates the use of a block 
 slightly larger than the plate, 
 and is objectionable for the pjg. 
 reason that the plate, not being held at the center, is liable 
 to bow and warp. A better way is to bore holes through the 
 mounting block about one or one and one-half inches apart, and 
 about three-eighths of an inch in diameter. At one end they 
 should be counter-sunk so that a cross section of a hole will be 
 
 in the shape of V, Fig. 42. The 
 zinc plate is then laid face down- 
 ward, and the back polished with 
 emery cloth. Lay the block above 
 it with the counter-sunk end of the 
 Pig- 42. holes upward, and clamp them 
 
 firmly together. In a small ladle, heat ordinary plumber's 
 solder, and pour it into the holes so as to barely fill them. The 
 
 T 
 
 I 
 
 T 
 
ROUTING AND FINISHING. 
 
 79 
 
 heat will be sufficient to fasten the solder to the plate, and the 
 counter-sink will attach it firmly to the block. It is best to put 
 a very little resin or a drop of soldering liquid at the bottom of 
 each hole. Care must be exercised not to make the solder 
 too hot, otherwise each point of attachment will show on the 
 face. The plate is now ready to be trimmed, which can best be 
 
 Fig. 43- 
 
 done in the machine shown in Fig. 43. Like the saw, the 
 spindle should make about three thousand revolutions per 
 minute. The cutters should be set so that they barely clear 
 the table, and that the cutting edges of the knives are horizontal 
 when half way through the block. The cutters used by electro- 
 typers for metal, although they will not make as clean a cut as 
 the grooved blades used for wood, are preferred, as the latter 
 
so 
 
 ROUTING AND FINISHING. 
 
 are rapidly dulled by the zinc. When re-ground, care should 
 be exercised to keep the cutting edge the original slant, to set 
 them firmly into the head at the correct angle, and the proper 
 distance from the sliding table. Tightening them into the head 
 
 Fig:, 44. 
 
 may cause them to shift position so as to cut into the table. If 
 there is any appreciable space between them, the edge of the 
 wood will be broken down and rounded. This is no serious 
 defect, but detracts from the appearance of the finished cut. 
 Some engravers avoid this by fastening a piece of electrotype 
 metal along the edge of the table with deeply counter-sunk 
 
ROUTING AND FINISHING. 
 
 81 
 
 screws. When the cutters are sharpened, they are set so as 
 to take a slight cut from this metal projection of the table, thus 
 preventing the edges of the cut from being rounded. In oper- 
 ating the trimmer, the set screws are loosened and the gauge 
 moved up so that a slight cut will be taken from the block. 
 The set screw in the rear of the gauge is then tightened. 
 Blocks are seldom sawed accurately, and always a little larger 
 than necessary. If the cut is not perfectly square on the block 
 a small piece of folded paper can be placed between one end of 
 it and the gauge, so as to throw it over. The operator stands 
 arms crossed before the machine, and with his right hand holds 
 the block firmly against the corner of the gauge. After the 
 first cut the left hand turns the gauge screw so as to push it 
 forward and take another small cut. After squaring the first 
 side the others are trimmed off close to the engraving. Where 
 space is an object, the combined saw and trimmer. Fig. 44, can 
 be substituted for the separate machines. New machinery 
 should be carefully watched to see that bearings do not get hot, 
 and as it wears, the bearings should be tightened up. Loose 
 pulleys should be oiled at least once a day, and rapidly revolv- 
 ing spindles, three or four times. The belt which passes over 
 the router spindle should be occasionally examined, and if it 
 shows signs of giving out, be replaced with a new one. As it 
 runs at a very high speed, it is liable to give the operator a 
 severe blow should it give way when running. 
 
 The use of metal bases is confined almost exclusively to 
 newspapers. For this purpose they should be exact column 
 
 Fig. 45- 
 
 widths, regardless of the width of the cut, and consequently 
 need not be trimmed on the sides. Solid metal bases will 
 answer very well, but on account of their great weight are not 
 generally used, except for half column cuts. Gored bases, 
 Fig. 45 representing a cross section of one, are much easier to 
 
82 
 
 ROUTING AND FINISHING. 
 
 handle, and less expensive. Bases may be purchased of 
 proper width and height, or may be cast in body molds made 
 for the purpose, in which case they must be shaved to accurate 
 height in the shaver. Fig. 46. The zinc should be fastened to 
 
 Fig. 46. 
 
 them with stout wire nails a quarter of an inch in length. 
 Small establishments can cut blocks with miter box and saw, 
 and square them with shoot-board and plane shown in Fig. 40. 
 
 The plates are now ready for the first proof. This need 
 not be very carefully made. The cut, together with the proof, 
 is then passed to the finisher, who examines it closely, and if 
 not certain on any point, refers to the copy from which it is' 
 made. For touching up, an eye glass, stand, and leather pad 
 are highly desirable, but not essential. The gravers should be 
 ground at a more obtuse angle than are wood engravers' tools, 
 
ROUTING AND FINISHING. 
 
 83 
 
 Otherwise the edge is liable to break off. There is some differ- 
 ence of opinion as to whether round or flat edge gravers are 
 best for this work. Tlie majority of finishers prefer the latter, 
 as the bottom of the tool can be used to touch up the sides of 
 lines where the relief is not sufficiently sharp. Frequently 
 some of the lines will be too heavy, and spots occasioned by 
 defective manipulation will appear. These must be carefully 
 cut out. Zinc is a very difficult metal to engrave. It 
 is by no means infrequent that the lines at the edges 
 of a cut print heavy. The most approved method of 
 lightening them is to run over them with a roulette, 
 Fig. 47. This instrument consists of a brass handle, 
 in the middle of which may be held various corrugated 
 wheels having sharp teeth of different sizes. Held 
 between the thumb and fore-finger of each hand, it can 
 be guided with light pressure so as to dot the lines. 
 Fig. 48 shows a cut before being treated with the rou- 
 lette, and Fig. 49 the same cut afterwards. The im- 
 provement can easily be seen. Many artists, how- 
 ever, object to the slightest change in the copy. After 
 being carefully retouched the cut is ready for final 
 proof. A Washington hand press is best for this pur- 
 pose, but an army press can be made to answer. 
 Usually one of the former can be purchased second- 
 hand at a reasonable price. It will pay to give careful 
 attention to the proof, as it is by this that the customer 
 will form his opinion of your work. Clean the ink slab 
 very carefully and distribute a very small quantity of 
 ink with a good roller. Heavy coated paper is gen- 
 erally employed for this purpose, consequenly the ink, 
 though an intense black, should not be too thick. Dis- 
 tribute it carefully over the surface of the cut. Place Fig. m. 
 this in the center of the press, and around it, several old cuts 
 to act as bearers. If the cut is heavy in the center, and has 
 but few outrunning lines, a portion of the ink may be removed 
 from the latter with the tip of the finger or a light dabber. 
 Place the paper carefully upon the block, and above it, ten or 
 fifteen sheets of smooth heavy paper, lower the tympan and 
 roll the bed beneath the platen. Give a good light impression, 
 and if the proof is not perfect, try again until you have secured 
 as good results as are possible. 
 
84 ROUTING AND FINISHING. 
 
 The thin zinc plates are extremely liable to warp, and where 
 the lines are isolated they are in printing often driven into the 
 
 Fig. 48. Fig-. 49. 
 
 wooden block. Whenever the edition is a large one, an elec- 
 trotype should be made and the original cut preserved. 
 
CHAPTER X. 
 
 Printing with Asphaltum, 
 
 As has before been noted, asphaltum was one of the first 
 substances to be used in photography. For the finer grades of 
 work it is still largely used in place of the bichromatized albu- 
 men for printing on zinc. The greatest objection to be urged 
 against it is the length of time required for exposure. Formerly 
 this was several hours, but modern methods of extracting the 
 less sensitive portions have reduced the time, so that it now 
 requires much less time. The advantage is that unlike 
 the albumen print, which is developed by rubbing off the sur- 
 plus ink, there is no danger of spreading the lines in manipula- 
 tion. 
 
 This substance is known as Egyptian asphaltum, Syrian 
 asphaltum, and bitumen of Judea. It varies greatly in respect 
 to sensitiveness. The best quality is of a deep brown color, 
 approaching black, but the edges of the lumps where rubbed 
 appear much lighter. When broken, the surface shows fine 
 shell-like configurations. Samples which appear the same vary 
 so greatly that it is advisable to purchase this material sen- 
 sitized and prepared for use, from some photo-engravers' supply 
 house. If you wish to make it yourself, procure asphaltum of 
 the finest quality, break it into small lumps and place it in a 
 large, wide-mouthed bottle. Pour in about four or five times 
 its bulk of concentrated sulphuric ether, stir thoroughly and let 
 it stand for a few hours, stirring it frequently until the ether 
 has absorbed some of the asphaltum and is turned a deep brown 
 color. This liquid must be poured off, more ether added, and, 
 with occasional stirring, the bottle allowed to stand for a some- 
 what longer period. If the asphaltum is of a good quality, this 
 fluid will be a great deal lighter in color than the first. It must 
 be poured off and replaced with fresh, and this process con- 
 tinued until the ether though frequently stirred is but very 
 lightly colored. It is then poured off, and the solid mass re- 
 
 85 
 
86 
 
 PRINTING WITH ASPHALTUM. 
 
 maining at the bottom allowed to dry. The fluid of the last 
 few washes may be preserved for the first washing of another 
 lot of asphaltum : the balance is of no value. When entirely 
 free from ether, dissolve one ounce of the powdered residue in 
 fifteen ounces pure benzole. Filter through cotton, filtering 
 paper or, preferably, chamois skin, into a yellow bottle. All 
 these operations had best be carried on in dark room No. 2. 
 The solution is now ready for use. In some varieties of asphal- 
 tum the extraction of less sensitive parts by ether leaves the 
 residue so brittle that it will not adhere to the plate. In such 
 cases a small quantity of oil of lavender or Venice turpentine, 
 previously boiled to expel the water, must be added to the ben- 
 zole solution. 
 
 Polish the zinc and copper thoroughly. Then take the 
 plate into the dark room and flow the coating of asphaltum over 
 it, as with collodion, taking care not to run over any part of 
 the surface more than once. As the benzole evaporates quite 
 rapidly, it is difficult even for an expert to coat a plate evenly 
 in this manner. A much better way is to purchase a whirler, 
 shown in Fig. 50. After the plate has been cleaned, place it in 
 
 the center of the disc, clamping it down by the edges, as illus- 
 trated in the cut. Now pour sufficient solution upon it to cover 
 two-thirds of the surface, then revolve the hand wheel as rapidly 
 as possible until the plate has dried. This will take but a few 
 moments, and on removing it the plate will be covered with a 
 thin coating of a golden color. Streaks or spots are generally 
 caused by the benzole containing a small amount of water. 
 After the solution is a few days old, plates may show minute 
 dark spots. These are caused by decomposition of the solution. 
 The remedy is to filter it immediately before using. The plate 
 
 Fig. 50. 
 
PRINTING WITH ASPHALTUM. 
 
 87 
 
 may now be slightly warmed, so as to drive off all the benzole. 
 It is then ready for printing. This must be done in the print- 
 ing frame, and in the same manner as with albumen. The ex- 
 posure will vary from fifteen minutes in direct sunlight to two 
 or three hours in diffused light. It can only be ascertained by 
 experience, and will vary with different samples of asphaltum, 
 or the same lot treated differently. Pour rectified turpentine 
 into a shallow porcelain or glass dish, to the depth of about 
 one-fourth inch, and then lay the exposed plate into it. Rock 
 the tray gently, when the print will gradually make its appear- 
 ance. When the whites appear clear, remove the plate and 
 plunge at once into the dish of water. Wash well under the 
 tap and examine with a strong glass. If not sufficiently devel- 
 oped, blot off the water, replace in the tray, and continue as 
 before. Should only part of the print be backward in develop- 
 ment, rub lightly over the surface with a small piece of ab- 
 sorbent cotton dipped into the rectified turpentine. When com- 
 pletely developed, the entire plate will appear as if covered 
 with a scum. Place it in a bath of benzine. This will remove 
 the remaining turpentine and leave a clear sharp print. Wash 
 off the benzine with water, blot off the surplus moisture and 
 expose the plate to sunlight for ten or fifteen minutes. This 
 will harden the asphaltum and turn it somewhat darker in color. 
 It is then ready for etching as directed in the previous chapters. 
 The first etch should be of comparatively weak acid, and should 
 not be continued for a long period. Before the second etch the 
 plate should be gummed up, as before directed. Should the 
 image be weak, or should it fail to develop at all, the entire 
 surface washing away, the print was under-exposed and another 
 one must be made. If the plate develops with difficulty, or 
 not at all, the trouble was over-exposure or, what is more prob- 
 able, the negative was not sufficiently intense. In general, it 
 is to be noted that over-exposure is not nearly so much to be 
 feared as under-exposure. 
 
CHAPTER XI. 
 
 Half-Tone. 
 
 This is at once the most interesting and difficult engraving 
 method. Not only are skill, attention and experience neces- 
 sary, but the result will also depend largely upon the operator's 
 artistic ability. In most instances the work will be portraits or 
 landscapes with photographs for copy. These should present 
 rich contrasts and be full of detail. A certain proportion of the 
 copy is cut out by the screen, consequently the resulting plate 
 will be weaker than the original. Pure whites cannot be ob- 
 tained without sacrificing the details of the darker parts except 
 by routing, and unless the copy presents rich contrasts the 
 plate will look flat and uninteresting. Often the copy may be 
 improved by touching it up with Chinese white, but this requires 
 a skillful artist. Experience will soon teach you what copy to 
 reject as unlikely to produce satisfactory results. 
 
 There are a number of methods of changing the tones into 
 lines or stipples. Generally a modification of the Meisenbach 
 process is used. \n the original method an ordinary negative 
 is first made. This is placed in contact with another sensitive 
 (dry) plate and a dia-positive made from it. This dia-positive 
 or transparency is placed in the front of an enlarging and 
 reducing camera. Fig. 6, with the lens back of it. It is then 
 focused on the ground glass. When the image is sharp and of 
 the correct size the sensitized collodion plate is placed in the 
 plate holder, and immediately before it, separated but a short 
 distance, tlie screen plate, having fine lines ruled in one direc- 
 tion. The plate is then exposed. If it is desired to make a plate 
 having the tones in the form of dots instead of lines the plate 
 is exposed but for a short time, and taken to the dark room 
 where the screen is given a quarter turn, the sensitive plate 
 remaining in the same position. It is then given another ex- 
 posure either the same length of time or a shorter period accord- 
 ing to the result it is desired to achieve. If properly exposed 
 
 88 
 
HALF-TONE. 
 
 89 
 
 this plate will have, instead of the delicate shadings of the 
 original, dots and lines which give the same effect. The varia- 
 tion of this method which follows is much simpler, quicker and 
 less expensive. While better detail and contrast are secured 
 by using screen plates ruled in one direction only, and exposing 
 twice, approximately the same results can be obtained by giv- 
 ing but one exposure behind a screen plate in which two series 
 of lines cross each other, and better modulation of tones will be 
 secured than by the double exposure. Screen plates are gen- 
 erally made on thin clear glass. The lines may be ruled through 
 some opaque material made to adhere to one of the surfaces, or 
 they may be etched beneath the surface and filled with some 
 dark varnish. Such screens are the best, as they can be fre- 
 quently cleaned. The great expense of their production and 
 the liability to break or scratch the glass prevents their general 
 adoption. Generally, photographic copies of such screens made 
 on collodion dry plates are used, as, if well made they work almost 
 as well as the original, and with careful handling will produce 
 a great many good negatives. Dust or splashes of silver allowed 
 to touch the prepared side will ruin them very quickly. As to 
 the proportion of lines there is great difference of opinion. The 
 closer they are together the nearer will the plate approach the 
 softness of tone of the original copy, but the more difficult will 
 it be to procure a perfect negative, make a good plate, and 
 print it after it is finished. Except on coated paper, with the 
 best ink and press work, the finest half-tone cut will have a 
 most unsatisfactory appearance. It has been found that one 
 hundred and twenty-five lines to the inch will produce dots 
 which will not be obtrusive. If made finer than one hundred 
 and thirty lines to the inch, the details will be better brought 
 out, but the results are apt to be unsatisfactory, except with 
 the most careful attention on the part of the pressman. Lines 
 as coarse as one hundred and ten to the inch will be hardly 
 apparent with such inspection as is given by the layman, and 
 will produce better contrast than those closer together. Screens 
 are sometimes made as coarse as eighty lines to the inch for 
 rough printing, but the result is hardly satisfactory. As to the 
 relative proportion of the black to the white lines on the screen, 
 there is also difference of opinion. Many workers who produce 
 excellent results prefer screens in which the white lines are 
 
90 
 
 HALF-TONE. 
 
 twice as heavy as the black lines. The majority, however, 
 prefer those in which the black lines are little lighter than the 
 transparent portions. Some prefer screens in which the lines 
 running in one direction are lighter or closer together than 
 those which cross them, as in such cases the lighter parts of 
 the middle tints change from crossed to single lines before 
 breaking into the dots composing the lighter tones, instead of 
 changing abruptly from cross lines to dots, as is the case when 
 both sets of lines are equal. If the screen were placed in close 
 contact with the sensitive plate, it can easily be understood 
 that the result would be the cutting out of such portions of the 
 plate as were covered by the opaque lines, while beneath the 
 transparent portions would be reproduced such parts of the 
 copy as were before them. If the screen were placed any con- 
 siderable distance away, yet still between the plate and lens, 
 the effect would be scarcely noticeable, as the light entering 
 the lens would pass around the opaque portions of the screen. 
 If, however, the screen is placed but a short distance before 
 the plate, say one-sixteenth inch, the light will, where it is 
 intense, work around those parts of the screen where the lines 
 cross, as well asthe portions between the junctions, breaking the 
 tints into lines and dots in the finished cut. The distance between 
 the screen plate and the negative depends largely on the rela- 
 tive proportions of the transparent and opaque portions of 
 screen, as also on the lens aperture. The only other articles 
 required besides those used for line work are the kits. These 
 are small frames made of well seasoned hard wood which fit 
 into the plate holder. In the corners of each frame are fitted 
 small distance pieces made of coin silver so situated that when 
 the kit is placed in the plate holder and the sensitive plate 
 pressed against the silver corners it will occupy exactly the 
 same position as if it were put directly into the plate holder. 
 Separate kits having distance pieces one-sixty-fourth, one- 
 thirty-second, three-sixty-fourths and one-sixteenth of an inch 
 in thickness are to be provided. As the frame must be stiff 
 enough to be rigid, the screen plate must be a size smaller than 
 the full capacity of the camera. Thus a ten by twelve camera 
 will admit a half-tone screen and sensitized plate but eight by 
 ten, an eleven by fourteen, one which is ten by twelve. As 
 the silver pieces cut off the corners, allowance must also be 
 made for these. 
 
HALF-TONE. 
 
 91 
 
 The utmost care must be exercised in making the negative. 
 The collodion should be made with the finest gun-cotton or 
 cellodine. The alcohol and ether as well as the salts should be 
 perfectly pure. It should be of the proper consistency and per- 
 fectly clear and free from foreign matter or hardened crusts. 
 The silver bath should be in perfect working order. Select a 
 kit with corners of moderate thickness, say three-sixty-fourths 
 of an inch. Place the screen plate in it so that the ruled side 
 will afterwards face the collodionized plate. Fasten it with the 
 clips and then secure it in the plate holder. Use an ordinary 
 copying camera shown in Fig. 5 and focus sharply on the copy. 
 If this is one of the modern photographs having a very highly 
 glazed surface, be careful to adjust the light in such manner that 
 it will not be reflected from the surface, otherwise it will be 
 impossible to secure a good negative. Make sure that the plate 
 is properly drained and then place it in the kit so as to face the 
 ruled plate. The spring in the back of the plate holder will 
 keep it in place. Take it to the camera and expose a little 
 longer than you would for an ordinary line negative. The 
 exact time cannot be given, as it will vary with circumstances. 
 Were the conditions exactly the same it would be possible to 
 give directions which would enable the beginner to determine 
 the proper distance and length of exposure, but as the apparatus, 
 screens, chemicals, diaphragms, light and— more than any of 
 these— the copies differ in every case, experience alone will 
 enable him to get good results. With the most successful half- 
 tone engravers it is largely a matter of instinct, yet often they 
 make several negatives of a fine piece of work before they 
 secure one which is satisfactory. Usually it takes from once 
 and one-half to twice the exposure required for line work. In 
 general it may be noted that if in the negative the black lines 
 of the screen plate are too distinctly reproduced, so that there 
 will be little contrast, the screen was too near the sensitive 
 plate or the aperture of the lens was too small. If, on the 
 contrary, the lines are not sufficiently distinct and the sj)aces 
 between them are filled in not with black dots of varying size, but 
 with deposits of silver of uniform extent, and varying in intensity, 
 the screen was too far from the plate or the aperture of the lens 
 was too large. When a good negative has been produced the 
 printing plate may be made by etching or by the gelatine 
 
92 
 
 HALF-TONE. 
 
 processes afterwards described. Generally it is etched on zinc 
 or copper. Here also the utmost care must be exercised. The 
 plate must be polished and buffed until the surface is perfectly 
 flat and free from scratches and indentations. The print should 
 not be made from a film, the printing frame must be used. 
 Asphaltum is preferable as the development is not likely to 
 blur the lines. 
 
 The smallest defect in manipulation, a speck of dirt on the 
 screen plate, negative, or in the printing solution will result in a 
 black or white dot in the printing plate and unlike line work it 
 is almost always disastrous to touch up the print or the finished 
 block, the correction being almost certain to show. The print 
 should be somewhat stronger than the finished cut. Use very 
 dilute acid, not stronger than one-fourth of an ounce to a quart 
 of water. The duration of the etch must be prolonged until 
 sufficient relief is obtained without losing the finer dots which 
 will become somewhat lighter. Generally half an hour is 
 sufficient. During this time the plate must be closely watched 
 through a magnifying glass, and if the fine dots show signs of 
 giving way the etching must be stopped. Some etchers gum, 
 ink and powder up, making two etches, but generally the re- 
 quired depth is given by a single bite. Powdering four times 
 is impracticable for half-tone work. The plate is now ready to 
 be mounted in the usual manner. As has before been noted, 
 pure whites cannot be obtainted in half-tone without sacrificing 
 detail in the shadows. When desired, such portions of the 
 print on metal, before etching, must be cleaned with scrapers 
 of different shapes. Unless this is done by some one of con- 
 siderable artistic skill the result is apt to be bad. If the original 
 has good contrast, pure whites will not be necessary to obtain 
 a satisfactory effect.. The whites may also be removed by 
 graver and routing tool after the cut has been etched and 
 proved. In such case the edges are apt to be sharp and harsh. 
 They can be softened down after mounting by the judicious use 
 of the matting punch held securely against the corners and 
 tapped so as to lower them and ease the impression at these 
 points. The less retouching required, the better will be , the 
 result. If properly made there will be a very few shadows of 
 pure black, semi-tones formed by black lines of varying thick- 
 ness crossing each other, and in the lighter portions fading into 
 
HALF-TONE. 
 
 93 
 
 minute black dots. Occasionally even the very best negatives 
 will be lacking in detail in the darker portions. This can be 
 remedied by the judicious use of a pencil roulette, Fig. 5 1 , making 
 a few fine dots. Should any portion be too 
 light it can be strengthened by the use 
 of a steel burnisher, Fig. 52. This will 
 make the printing plate lower at such 
 points, but not enough to affect the print- 
 ing. Small dots can be removed with a 
 finely pointed graver, but if the screen 
 is a good one and the plate properly 
 made they will seldom appear. Small 
 white spots are often present in the best 
 cuts, but if dust is carefully excluded 
 they will be so infrequent as to be un- 
 noticed. Very often the cut can be im- 
 proved by painting a border around it 
 with a mixture of etching ink and turpen- 
 tine. If the border is to consist of straight 
 lines, this can be done with a ruler, the 
 entire margin being covered before the 
 plate is etched. If in the form of an oval 
 or circle, a glass pattern is generally em- 
 ployed. If the cut has been etched, the 
 margin is routed out so as to leave a black 
 line surrounding the cut. This can be 
 trimmed up either on the shoot-board or 
 with a graver. Both zinc and copper 
 being very tough, the formation of perfectly smooth lines in- 
 volves considerable skill and care. If no black line is desired 
 the border is scratched in the etched plate. This is a much 
 easier method. The use of a prism or reversing mirror, referred 
 to in the next chapter, is highly desirable for half-tone nega- 
 tives. For fine work, making a print on copper by asphalt and 
 etching with perchloride of iron, as before referred to, will be 
 found most satisfactory. 
 
 Fig. 52- 
 
CHAPTER XII. 
 
 Miscellaneous Hints. 
 
 In the preceding chapters the zinc etching process has 
 been carefully outlined. For a number of reasons it is the most 
 desirable method of relief engraving. Gelatine swell and gela- 
 tine washout require skill and experience which cannot easily 
 be obtained without long apprenticeship, and, except for certain 
 classes of work, are not nearly so good. Therefore they will 
 not be treated at length in the following chapters. A few 
 words further, however, as to economical methods in working 
 the first named process, and negatives for all of them, will not 
 be out of place. 
 
 It should be remembered that it costs no more to photo- 
 graph several drawings on the same plate than a single small 
 one. Wherever possible, all copy having the same amount of 
 reduction should be saved until enough has accumulated to fill 
 the copy board. Even where this cannot be done, films should 
 be saved until enough have accumulated to print one-third or 
 at least one-fourth of a sheet of zinc, as it takes little more time 
 to etch a large sheet than a small one. Rough and fine work 
 should not, however, be put on the same piece, as the latter 
 would be sure to suffer in the etching. 
 
 An establishment in which one man does all the work, from 
 polishing the zinc to blocking the cut, cannot hope to compete 
 with one in which the work is divided amongst a number of 
 employes. Few can both photograph and etch perfectly. In 
 most shops the work is divided into these two departments, and 
 in the majority there are three more, viz: zinc polishing, zinc 
 printing and blocking. Where there is sufficient to still further 
 divide it, the best results can be obtained at the least expense. 
 Often in small establishments it will pay better to have part of 
 the work, such as zinc polishing, routing and blocking, done by 
 other parties. The materials used, though sometimes expensive, 
 are, with the exception of zinc, used in such small quantities 
 
 94 
 
MISCELLANEOUS HINTS. 
 
 95 
 
 that they do not materially affect the cost. It will not pay to 
 economize by purchasing them of inferior quality. When such 
 articles as etching ink, stripping solution, etc., can be obtained 
 prepared at reasonable prices and of superior quality, it will 
 not pay to make them. Should it be necessary to change them 
 slightly for some special experiment, their composition can 
 quickly be learned. 
 
 If lead pencil marks are run on the ground glass of the 
 camera horizontally and vertically, so as to cross each other at 
 the center, and are then marked off into inches, it will greatly 
 facilitate the proper reduction. It is also a good idea to mark 
 the camera slide and stand at the point where the camera will 
 make the reduction of one-half, one-third, one-fourth and other 
 common sizes. 
 
 But a very small proportion of the silver is actually used, 
 as the balance runs away in the sink. Many photographers 
 precipitate the washings in a tank, allow them to settle over 
 night, and then drain off the water above them. The muddy 
 precipitate is taken out at intervals and, together with the other 
 wastes, sent to the refiner. Very few photo-engravers take 
 the trouble to do this, but usually the blotting paper on which 
 plates are drained, and with which the back is cleaned, and the 
 paper or cotton through which the bath is filtered, are kept 
 until an appreciable amount has accumulated. Should the sil- 
 ver bath be in very bad shape, it will often pay better to pre- 
 cipitate by adding saturated solution of common salt until the 
 settled water is no longer turned milky on the addition of more 
 salt, and send it to one of the many firms who make a business 
 of refining such wastes. 
 
 It sometimes happens that an order is received for making 
 a plate in which the design appears white on a black ground. 
 If the copy is on white paper, and the design opaque, it can 
 often be used instead of a negative by placing it in contact with 
 the sensitized metal plate in the printing frame, and giving it a 
 somewhat longer exposure than required for an ordinary print. 
 The paper may be rendered more transparent by soaking in 
 turpentine and oil. If you have the original printing block, a 
 proof may be taken on thin white paper with black ink, and 
 rendered still more opaque by bronzing it before the ink is dry. 
 Should a reduction be required, make a negative. From this a 
 
96 
 
 MISCELLANEOUS HINTS. 
 
 positive can be made by contact with another sensitized plate, 
 but as the silver solution would spoil the negative, gelatine dry 
 plates are best. The operator can procure plates and expose 
 and develop them himself, but as such jobs are rare it will not 
 pay to fit up a dark room for dry plate work, and it will gene- 
 rally be found more economical to have some portrait or land- 
 scape photographer make the positive. There are methods by 
 which the print on zinc can be changed so that the white por- 
 tions will appear black and the black portions white, but, as 
 above stated, on account of the infrequency of such work it will 
 not pay to fit up for it. If it is desired to make a cut left- 
 handed, it can be done by printing on the zinc directly from the 
 negative without stripping and turning it. This is sometimes 
 very useful when making borders from original drawings, as 
 but one-half of the design need be drawn, and two negatives 
 having been made and stripped, one of them can be turned and 
 both films matched closely together for making the print. 
 
 In some establishments mirrors or prisms are used to 
 obtain reversed drawings without stripping. The idea is illus- 
 trated in Fig. 53. The camera is so mounted on an L shaped 
 
 Fig- 53- 
 
 swing or stand that the opening in the prism will face the cen- 
 ter of the copy-board. As considerable light is lost in trans- 
 mission, the exposure requires from one-fifth to one-half more 
 time than without the prism, depending upon the make and 
 arrangement. The proper size is given the negative by mov- 
 ing the copy-board, not the camera, the front of which is sta- 
 
MISCELLANEOUS HINTS. 
 
 97 
 
 tionary. Focusing is accomplished in tlie usual manner, i. e., 
 by moving the back of the camera. After drying, the negative 
 is usually varnished to prevent its being scratched. The print 
 is made in the frame in the usual manner. For half-tone, such 
 negatives are preferable, as there is less danger of injury or 
 distortion than if the film were stripped, but it is seldom used 
 for line work on account of the longer exposure, and because it 
 is more economical to strip the films and print a number on a 
 large sheet of zinc than to print separately from each negative. 
 
 Zinc rapidly oxidizes in the atmosphere, and becomes 
 covered with a gray coating. To a certain extent this will pre- 
 vent further oxidation, but if kept in a damp place the plates 
 will become coated with a white deposit, and rapidly deteriorate. 
 If they are to be preserved for any length of time, the surface 
 should be rubbed with a very little tallow. Another way which 
 also adds greatly to the attractiveness is, to coat them with 
 copper. This can be done in the battery by using a solution 
 of cyanide of copper. It can also be accomplished by the fol- 
 lowing method. Prepare a bath by dissolving ten ounces of 
 chloride of copper in six ounces of water. Add to this fifteen 
 ounces concentrated water ammonia and three hundred ounces 
 of water. This solution will have a bright blue color. Add to 
 it concentrated solution of cyanide of potassium until the color 
 has almost disappeared. Pour a little of this bath into a shallow 
 tray, and in it lay the zinc etching, which has previously been 
 carefully cleaned with benzine, and afterwards with chalk and 
 ammonia. In a few moments it will become covered with a 
 bright deposit of copper. Leave it in for five or ten minutes, 
 then wash thoroughly under the tap and dry with hot saw- 
 dust. It is of course understood that the coating of copper is 
 very thin, and therefore will not add materially to the strength 
 of the plate, but a thick coating cannot be given without 
 detracting from the sharpness of the cut. This preparation 
 deteriorates rapidly and should be fresh. 
 
 Zinc is not only harder than type metal, but has more 
 elasticity. This makes etchings much more difficult to print 
 than electrotypes or stereotypes, and the defect is aggravated 
 by the use of such thin metal. Whenever long runs are to be 
 made, it will always pay to have an electrotype made from the 
 original. 
 
98 
 
 MISCELLANEOUS HINTS. 
 
 For economy's sake, nitric acid and distilled water should 
 be purchased in carboys. An acid pump for filling bottles from 
 them would be an excellent investment. 
 
 Stains on the fingers are almost unavoidable. Those made 
 by acid cannot be removed except by rubbing off the epidermis 
 with a piece of pumice stone. Silver stains caused by photo- 
 graphy are generally removed by wetting and rubbing them 
 with a lump of cyanide of potassium. This is a most dangerous 
 proceeding, as the cyanide is an intense poison, and may cause 
 sores which are difficult to heal. Although many people are 
 not affected by it, a better way is, to mix three ounces tincture 
 of iodine and one ounce concentrated water ammonia. When 
 the liquid becomes clear, it is ready for use. With some people, 
 the bichromatized zinc printing solution will also produce pain- 
 ful sores, and care should be exercised to prevent cutting the 
 fingers on the glass when using it. 
 
 DRAWING ON ZINC. 
 
 It sometimes happens that there is not sufficient time to 
 make a negative and print on zinc in the usual manner. In 
 such cases the drawing can be made directly upon it. Procure 
 a stick of tuche, sometimes called lithographer's drawing ink 
 (Vanhymbeck's is excellent), and rub it in a shallow dish until 
 the bottom is covered with a thin layer. Now add a few drops 
 of clean water and rub thoroughly together with the tip of your 
 finger, it should be of the consistency of cream and perfectly 
 opaque. Grain the zinc as if for etching, and draw upon it with 
 a common steel pen. Be very careful not to touch the surface 
 of the zinc with your fingers or anything greasy. It is best to 
 use the retouching board for this purpose. When the ink is 
 perfectly dry, gum up the plate as described in Chapter VIII, 
 fan the gum dry and then roll up with No. 2 etching ink. At 
 first the lines will disappear, leaving a bright metal surface. 
 Gradually they will take ink and become black. In the mean- 
 time the gum sponge must be freely used, to prevent the ink 
 from taking hold of the blank spaces. When the lines have a 
 good coating of ink, the powder is dusted and melted on, and 
 the etching can proceed as if the print were produced photo- 
 graphically. Tuche is difficult to work, and this method can- 
 not be used on fine jobs. 
 
MISCELLANEOUS HINTS. 
 
 99 
 
 SILVER PRINTS. 
 
 Preparing silver prints does not properly come within the 
 scope of this manual, but almost every photo-engraver who 
 does original work is required to make them. Procure a good 
 quality of salted paper from a supply house. Prepare the sil- 
 ver bath by dissolving nitrate of silver in distilled water until 
 the hydrometer registers forty-five grains to the ounce. Place 
 this solution in a glass tray on one end of which is affixed a 
 glass rod, and draw a paper through it in such manner that the 
 surface of the paper will pass through the bath several times. 
 Always select the side which is most suitable for drawing. 
 Hang it in the dark room by means of clips. As soon as dry, 
 it is ready for use, but some first expose it to the fumes of 
 ammonia, as this makes it more sensitive. It should be freshly 
 prepared every day. Make the negative once and a half or 
 twice the size the cut is intended to be when finished. Expose 
 the sensitized paper beneath the negative in an ordinary print- 
 ing frame. The time will depend upon the light. When suf- 
 ficiently exposed, wash it in a tray containing two ounces of 
 salt dissolved in one quart of water. When the print has turned 
 red, take it out and wash in a tray containing a solution of one 
 ounce of hyposulphate of soda and six ounces of water. Then 
 . wash in running water for at least ten minutes. When dry, 
 attach the print to a piece of card-board by means of starch 
 paste. After the artist has drawn upon it, and his ink has 
 thoroughly dried, place it in a tray containing concentrated 
 solution bichloride of mercury in alcohol, to which add a few 
 drops of hydrochloric acid. Rock the tray gently until the 
 paper is bleached its original color, then remove the drawing 
 and wash it in running water for at least five minutes. When 
 dry, it may be returned to the artist for retouching. 
 
 THE MEZZOTYPE PROCESS. 
 
 This is the name given to a class of engravings in which 
 the tones are produced by means of fine dots, the effect resemb- 
 ling, more than anything else, lithographic crayon work. There 
 are several ways in which the work can be done. i. The 
 design may be drawn on stipple paper with lithographic crayon, 
 and from this a negative made and printed on zinc in the usual 
 manner. 2. The zinc may be grained with emery in the same 
 manner in which a lithographic stone is roughened, and the 
 
100 MISCELLANEOUS HINTS. 
 
 drawing made directly upon the zinc with crayon. 3. A half- 
 tone negative may be made by the intervention of a screen in 
 which the lines are not straight, but irregularly disposed. 
 4. From an ordinary negative a print may be made on a thin 
 sheet of gelatine, and this gelatine broken up into a grain by 
 mechanical or chemical means. There is little demand for the 
 result of any of these processes, so they will not be described. 
 For certain classes of work, however, such as railroad hangers, 
 it is desirable to produce effects similar to those of lithography, 
 yet print the engravings on a type press. In such cases the 
 second method above mentioned is sometimes used, but usually 
 the so-called mezzotype or color process is employed. The 
 results will depend not only upon the operator's ability as an 
 etcher, but upon his skill as an artist and his knowledge of 
 color effects. The width of the powdering box is somewhat 
 greater than that of the widest zinc plate. The length corres- 
 ponds with that of the plate, and the height is the same as 
 the length. To the centers of its two sides are affixed journals 
 which are supported by a stand, in the front of the box, near 
 the bottom, is placed a small door which can be closed tightly, 
 and even with the bottom of the door are several rows of wire. 
 To operate the box, a small amount of powder is put in it. 
 Ordinary dragon's blood will answer, but many prefer one 
 which is made up of mastic, asphaltum and bees-wax, melted 
 together and powdered. The box is revolved a number of 
 times, so that the powder will be agitated and thoroughly dis- 
 tributed throughout the interior. The box is then fastened into 
 position and allowed to rest for a few minutes until the coarser 
 particles of the powder have settled at the bottom. The door 
 is opened and the zinc plate slid in upon the wire face upwards. 
 After a few moments the plate is removed, when its surface 
 will be found covered with small bits of powder evenly dis- 
 tributed. If the tint is not dark enough, the plate is replaced 
 and allowed to remain until enough powder has fallen. It is 
 then carefully taken to the etchers' oven and heated thoroughly. 
 Great care must be exercised at this point. If the heating is 
 carried too far, the spaces between the dots will be covered 
 with a resinous distillation from the powder, and will resist the 
 acid. If not heated sufficiently, the powder will not adhere well 
 enough to protect the metal. After heating, the plate should 
 
MISCELLANEOUS HINTS. 
 
 101 
 
 have a velvety appearance, the dots partly hanging together 
 and showing the bare zinc between them. The etching is done 
 in the usual manner with weak acid and without brushing. If 
 very coarse dots are desired, coarse powder must be used, but 
 it should also be noted that the longer the box is allowed to 
 rest before introduction of the plate, the finer will be the dots, 
 as the coarser particles will settle at the bottom first. The 
 above procedure is employed when a plate of even tint is de- 
 sired. Its use is limited, being sometimes applied to making 
 borders around zinc etchings, in which case the border is first 
 painted over with lithographic ink dissolved in turpentine, and 
 after the cut is completed the ink is washed off and the design 
 itself painted over, so as to leave the balance of the zinc ready 
 to receive the mezzotint powder. It is also used in cases where 
 the proof of a finished half-tone engraving shows a back-ground 
 or sky which is too dark. After protecting the body of the 
 engraving from the acid in the usual manner, the plate is pow- 
 dered and again etched. For color work the design of the black 
 or key plate is generally transferred to the surface of the zinc 
 by making a print from the negative and powdering in the 
 usual manner. A slight etch is made, after which the surface 
 is cleaned, leaving the design in bright lines on a dull surface. 
 If there is no negative of the key plate, take a proof on stout 
 paper and place its face in contact with a zinc plate. Now run 
 the plate and proof through a lithographic hand press under 
 strong pressure. Enough ink will be transferred to the surface 
 of the metal to permit its being powdered and etched as before. 
 After cleaning, the artist paints the plate ^ith etching ink and 
 turpentine, excepting only such parts as he desires shall not 
 print at all but remain white. After powdering and melting, 
 these spaces are etched and routed out in the usual manner. 
 The plate is again cleaned, and this time the artist paints in 
 the parts which he intends shall be solid or black. After dust- 
 ing these parts with powder the plate is placed in the dusting 
 box and sufficient powder allowed to settle upon it to give a 
 moderately dark tone. The etching is performed in the usual 
 manner. It will be noted that the resulting plate will have but 
 three tones. Solid black, white, and a gray middle tone. If 
 it is desired to make variations in this last tone, such parts of 
 it as are right may, after the first etch, be painted over with 
 
102 
 
 MISCELLANEOUS HINTS. 
 
 etching ink and turpentine, and powdered, after which the plate 
 is placed in the acid, which will lighten the dots of the remain- 
 ing surface by slightly under-cutting the edges. By painting 
 and powdering over additional portions, still lighter tones may 
 be secured in parts by a third etch. This procedure must be 
 repeated for each color block. The beautiful color work of 
 French illustrated papers is the result of a combination of the 
 above method with half-tone. The copy is usually a wash 
 drawing or a painting. From this are made a number of half- 
 tone negatives. For the black or key plate a cross line screen 
 is invariably used, but for the lighter color plates a single diag- 
 onal lined screen is often chosen. After making the prints on 
 zinc the artist strengthens such parts as he desires shall produce 
 solid tones and scrapes out the high lights. If very light tints 
 are desired the plate is dusted in after the half-tone plate has been 
 etched, and in this way a tint plate produced which will not 
 interfere with the lines of the key. Such parts as are desired 
 solid must of course be painted over. Considerable skill and 
 judgment are necessary to obtain good effects, and unless the 
 operator is thoroughly acquainted with color work the results 
 are almost certain to be unsatisfactory. 
 
CHAPTER Xill. 
 
 Double Washout Gelatine Engraving. 
 
 As compared with zinc etching, all gelatine methods are 
 slower and more difficult. The washout processes are perhaps 
 the most desirable. Nevertheless it takes at least eight hours 
 to produce a cut, and the process cannot be economically 
 worked, except in establishments where a large quantity of 
 work is done, so that some is constantly under way, and in 
 every stage of completion. A single cut would cost far more than 
 a single zinc etching. Besides this, gelatine is difficult to 
 handle, atmospheric conditions and temperature affecting the 
 work to a great extent, so that only in a well fitted room can a 
 man of long experience do good work economically. The gela- 
 tine plate can be used for printing small editions, but is com- 
 paratively fragile, therefore an electrotype should be taken 
 from the original. This involves the ownership, or at least the 
 proximity, of such a plant. While all classes and grades of 
 work can be done, it is particularly adapted to the reproduction 
 of book plates. Even on ordinary type matter, the cost of pro- 
 ducing a plate is less than that of composition, and where 
 foreign quotations or accents are frequent, or where there are 
 engravings in the text, the gain is large. The cheap American 
 editions of the Encyclopedia Britannica, and the reprint of Web- 
 ster's Unabridged Dictionary, may be cited as works which 
 were economically reproduced by this process. 
 
 hi the simplest form of the process, the sheet of gelatine, 
 after exposure to sunlight, is brushed out but once to procure 
 the necessary relief. This will be treated of in the next chapter. 
 In the double washout method, after a small amount of relief 
 has been obtained the blank spaces or whites are filled with 
 some opaque substance, and the sheet again exposed to the 
 light, so that the rays will penetrate deeper and allow a second 
 washing, which gives greater relief without danger of losing 
 the lines. It is but fair to add that the idea of using an opaque 
 
104 DOUBLE WASHOUT GELATINE ENGRAVING. 
 
 paste was originated by Wm. IVlumler, of Boston, Mass., who, 
 on May iStli, 1875, obtained a patent. A number of photo- 
 engraving establishments have adopted the idea, and as the 
 patent expires upon the i8th of May, 1892, it may be used by 
 anyone after that date without fear of trouble. 
 
 The photograph gallery should be fitted up in exactly the 
 same manner as for zinc-etching, and the negative should be 
 made as described in former chapters. The work room should 
 be commodious and in as cool and dry a place as possible. All 
 light should be excluded except such as passes through what is 
 commonly known as yellow post-office paper. A better but 
 more expensive way is, to glaze the windows with orange glass, 
 and also cover them with yellow muslin curtains mounted on 
 spring rollers. Beneath the work table there should be a series 
 of drawers large enough to hold sheets of gelatine of sizes equal 
 to the largest piece of work which it is intended to do. There 
 should also be a large, deep sink provided with running water, 
 and having cross-bars a few inches from the top, on which the 
 gelatine sheets may be rested while washing out. Alongside 
 the sink should be a large table for the dishes and trays, and 
 above it, shelves for chemicals. A small closet should be par- 
 titioned off. \n this the gelatine is to be rotted. The following 
 utensils or apparatus must also be made or purchased. 
 
 THE DRYING BOX. 
 
 The size and construction of this will depend entirely upon 
 the location and the scale on which the work is to be carried 
 on. Large establishments devote the entire side of the room 
 to a series of shelves, through which dry air is drawn by means 
 of an exhaust fan. For experimental purposes, a large wooden 
 box having level shelves three inches apart, each of them four 
 or five inches wider one way than the setting frames described 
 further on, and having open spaces at alternate ends of the 
 shelves, so that the air will pass over the surface of every plate, 
 will do very nicely. The front of the box should be provided 
 with a door which can be closed air tight. \n the top and bot- 
 tom of the box are openings, and beneath the lower one is placed 
 a gas or oil heater. Fig. 54 shows a construction adapted to 
 large establi^iments having power. The end which opens into 
 the work room is provided with a muslin covered opening, M. 
 
I 
 
 DOUBLE WASHOUT GELATINE ENGRAVING. 10 o 
 
 At the other end, in the closet A, is set a rotary fan which 
 draws the air through the screen so that it passes over the 
 
 Fig. 54. 
 
 plates and out of the window at the end of the closet. 
 
 SETTING FRAMES. 
 
 These are made of the finest plate glass one-quarter inch 
 thick, perfectly level, and free from flaws. For large work 
 they may be 26x26 inches, so that one will answer for a pound 
 of gelatine. For experimental work, 10x12 will do. Around 
 each glass is a frame of ash 'or other hard wood, attached in 
 the same manner as the wooden rim of a school-boy's slate, 
 the edges being slightly beveled towards the inside, as illustrated 
 in Fig. 55. The wood should project five-eighths of an inch 
 
 Fig. 55. 
 
 above the surface of the glass. Should the joints be imperfect, 
 they must be filled with wax, otherwise the gelatine will creep 
 into the cracks and dry, and may at some future time absorb 
 moisture and swell so as to crack the glass or twist the frame 
 out of shape. Before using, the woodwork should be well 
 
106 DOUBLE WASHOUT GELATINE ENGRAVING. 
 
 waxed, otherwise the gelatine will run up the sides and harden, 
 adhering so firmly to the wood as to necessitate cutting into it. 
 
 Fig. 56. 
 
 A still better way is to have the frame made of tin, the edges 
 being beveled towards the inside, and the joints carefully and 
 smoothly made. This construction is shown in Fig. 56. 
 
 LEVELING TABLE. 
 
 This is a frame-work about three feet high provided with 
 a number of stringers through which thumb-screws pass — twice 
 as many in the back as in the front. The frames just described 
 are laid on three screws, the frame-work extending beyond 
 them. 
 
 ROTTING DISHES. 
 
 These are earthenware bowls such as used for mixing 
 dough and batter. Generally yellow-ware is used, as it is least 
 expensive. They should hold one or two gallons each, and 
 quite a number should be kept on hand. 
 
 POURING DISH. 
 
 This is similar to those described above, except that it has 
 a lip provided with a fine wire gauze strainer attached by means 
 of a band of tin around the upper edge. 
 
 FILTER CLOTH. 
 
 This is made of heavy, brown drilling, one yard square. 
 It should be hemmed on the edges to prevent fraying. Boil it 
 thoroughly and wring out before using. 
 
 WASHOUT BRUSHES. 
 
 These are similar in shape to watch-makers' cleaning 
 brushes, the brush portion being about four inches long, and 
 of medium stiff bristles. The best will be found most economi- 
 cal, as in the cheaper grades the bristles will soften and lie 
 
DOUBLE WASHOUT GELATINE ENGRAVING. 107 
 
 down when wet. For the first washing a brush with three or four 
 rows will answer, but for brushing away the black paste and 
 giving the second washout, brushes having eight or ten lines 
 of bristles are more economical. 
 
 ALCOHOL TRAYS. 
 
 These should be deep trays, and are preferably of porcelain 
 of glass. Rubber trays will answer very nicely, and the coated 
 wooden trays known as "common sense" can also be made to 
 answer. It is economical to have them large, so that they will 
 hold a large quantity of alcohol, otherwise they will absorb water 
 from the gelatine and soon require replacing. If rubber or 
 wooden trays are employed, the alcohol must be poured back 
 into the bottle immediately after using, and the tray thoroughly 
 washed with warm water until the greasy appearance has left 
 it, otherwise the alcohol will soften the rubber and cause it to 
 warp or blister. 
 
 SQUEEGEE ROLLER. 
 
 A rubber roller provided with a handle, and from six to 
 twelve inches long, should be purchased. Its use will be de- 
 scribed further on. A clothes wringer can be utilized for the 
 same purpose. 
 
 SPATULAS. 
 
 There should be at least three of these of different sizes. 
 They are used in removing the gelatine from the zinc after 
 electrotypes have been made, mixing and applying the filling-in 
 paste, cleaning dishes, and for numerous other purposes. 
 
 PRINTING FRAMES. 
 
 For small or experimental work the ordinary photographers' 
 deep printing frame, provided with wedges to place beneath 
 
 Fig. 57. 
 
 the springs, will answer nicely. For large work a heavy frame 
 similar to that used for printing on zinc, or of the construction 
 shown in Fig. 57, is preferable. It must be deep enough to 
 
108 DOUBLE WASHOUT GELATINE ENGRAVING. 
 
 admit the pressure bag. During cold weather a piece of heavy 
 felt or chinchilla cloth is placed between the pressure board 
 and the gelatine when printing, in warm weather the heat 
 of the sun is apt to melt the gelatine, causing it to creep or to 
 stick to the negative. To obviate this a rubber pressur-e bag 
 must be provided. It should be perfectly square at all corners, 
 flat on the surfaces, and should fit neatly into the printing 
 frame. Immediately before using, it is filled with cold water 
 and substituted for the felt, thus reducing the temperature of 
 the gelatine while the print is being made. 
 
 PRINTING BOXES. 
 
 These are boxes made of light wood, open at both ends, 
 one of which fits closely on the printing frame. The usual 
 length is three or four feet. They are painted black on the 
 inside. ■ When exposing the gelatine, the tube is fitted over 
 the frame, the opening of which is pointed to the light. Its 
 use will prevent side rays from penetrating the gelatine and 
 rendering it insoluble between the lines. The best construction 
 is one in which the box is mounted on trunnions so as to make 
 adjustment easy. 
 
 PRINTING BOARD. 
 
 This is an ordinary board provided with a small projection 
 at one end, and painted black. On this the prints are placed 
 after being filled in with paste for the second printing. Its use 
 obviates changing each print so as to face the light as the sun 
 changes position, and is also more convenient for handling the 
 prints, as the board can be lifted and a number carried about 
 without danger of their sticking together. 
 
 TALC BOX. 
 
 This is an ordinary tin spice box. It is filled with finest 
 
 talc. 
 
 PUMICE STONE BOX. 
 
 This is similar to the above. It is filled with the finest 
 powdered pumice and should be labeled so as to be distinguished 
 from the talc box. 
 
 ROTTING BOX. 
 
 A good size for this box is two and a half feet square and 
 six feet high. It is lined on the interior with zinc, sheet iron 
 or tin, so separated from the walls as to allow a draft of 
 cool air to circulate in the empty space, thereby preventing 
 
DOUBLE WASHOUT GELATINE ENGRAVING. 109 
 
 danger of fire. Fig. 58 shows the usual construction. At the 
 top are three shelves upon which are set the earthenware 
 dishes containing the gelatine which is being rotted. In the 
 door are set panes of glass A A, which permit inspection of the 
 
 Fig. 58. 
 
 interior, also a thermometer B, which can be seen from the 
 outside. C is a sliding board at the bottom, so arranged as to 
 permit the closing of the holes D D, thus regulating the draft. 
 E represents the gas heating stove, which is connected by the 
 hose F to the regulator G, and from thence to the supply pipe. 
 Fig. 59 shows 'an enlarged view of the regulator which is 
 attached to the inside of the box by a band of brass. It is 
 made of a heavy tube of hard glass, hito the neck is fitted a 
 rubber stopper 3, through which two smaller bent tubes i and 2 
 are passed. At the bottom of the test tube is placed some 
 mercury. It will be noticed that the bottom of the exit tube is 
 ground off at an acute angle. To set the regulator, the gas is 
 lit and the tube 2 pushed up or down until the thermometer 
 remains at 120°. The tube can then be marked at the proper 
 point with a sharp file. There are a number of other articles 
 which will be mentioned further on. 
 
 When everything is in order, procure a pound of Nelson's 
 amber gelatine in shreds, place it in one of the rotting dishes 
 and pour on enough filtered or distilled water to cover it well. 
 
110 DOUBLE WASHOUT GELATINE ENGRAVING. 
 
 About three and one-half pints will be right. Allow it to stand 
 until it has absorbed the water and swelled. Turn the mass 
 occasionally, otherwise it may dry in places. When thoroughly 
 soaked, place the dish in the rotting box and 
 carefully note the temperature. The amount 
 of rotting ca^inot be accurately described. If 
 the heat is kept at a uniform degree of 120° 
 F. it will take from twenty-four to thirty- 
 six hours. While it is rotting, lay a num- 
 ber of the setting frames on the leveling 
 table so that the bottom of each piece of 
 glass rests on three screws. By means of a 
 spirit level, preferably of iron, and six inches 
 long, level it perfectly. When the glass is 
 in position, see that it is perfectly free from 
 dirt or grease. If there is any doubt about 
 this matter, wipe it first with water ammonia 
 and then with alcohol, when it is ready for 
 waxing. Procure some pure, unrefined, ^g. 59. 
 
 yellow bees-wax, shave it very fine and place it in a glass-stop- 
 pered bottle. Cover it with concentrated sulphuric ether and 
 shake until it is dissolved. Continue adding wax until no more 
 will be dissolved. This is the stock bottle. For use, dilute it 
 with equal parts of ether and alcohol. Shake well, and it is 
 ready for use. The exact strength of this solution is not of 
 moment. A solution of wax in benzole may be substituted. To 
 wax the plate, pour some of the mixture upon the glass, hold- 
 ing the bottle in the left hand, and with a bit of cotton flannel, 
 twill side out, held in the right hand, rub with a circular motion 
 as though putting a French polish on hard wood. Never let 
 the cloth stop, and when raising it do so with a straight swing. 
 Should the wax chill and accumulate in spots, dampen a cloth 
 with a little of the ether and alcohol mixture, and rub until the 
 milky appearance has entirely left it, leaving a fine lustre. 
 
 Powder four drams potassium bichromate in a mortar, and 
 add two ounces warm water and from one-half to one dram of 
 water ammonia. Some operators use bichromate of ammonium, 
 omitting the water ammonia; others use a mixture of both. 
 This is the sensitizing solution. When the gelatine is suffi- 
 ciently rotted (something difficult to describe, but readily dis- 
 
DOUBLE WASHOUT GELATINE ENGRAVING. Ill 
 
 cernible to the experienced operator by its odor), add the above 
 quantity to the gelatine in the bowl, stirring constantly. Now 
 add about two ounces of glycerine, which gives flexibility to 
 the sheet. The quantity depends considerably on the tempera- 
 ture and the humidity of the atmosphere. Should too much be 
 added, it will, particularly in hot weather, lessen the sensitive- 
 ness and the solubility of the parts unacted upon by the light. 
 It will also cause the objectionable "creeping" which will be 
 described further on. If, however, the quantity is insufficient, 
 the sheet will be so brittle as to crack and split while being cut 
 with the shears, although in this case the difficulty can often 
 be overcome by warming the sheet before cutting. Assure 
 yourself that the setting frames are thoroughly coated, perfectly 
 level and clean. Gather the straining cloth by the four cor- 
 ners and, holding it over the pouring dish, pour the warm gela- 
 tine into it. It will come through with difficulty, and must be 
 forced by twisting the bag in the same manner as adopted in 
 domestic establishments when straining starch or jelly. Take 
 a small piece of clean card-board about the size of a visiting 
 card, rounded at the corners, dampen slightly with warm water, 
 and with it skim the bubbles to one side of the dish and rake 
 them over the side of the bowl into the water. See that the 
 gelatine is perfectly clean. Pour into the setting frames either 
 by beginning at the center and pouring with a circular motion 
 until the frame is full, or pouring on one side and tilting the 
 frame so as to allow the gelatine to flow evenly and smoothly 
 until it reaches the other side. If the gelatine be too cold or 
 too thick it will set unevenly and in ridges, and if these faults 
 be pronounced, it will not flow to the edges before it sets. If 
 it is too warm, it is liable to melt the wax and make the sheet 
 of gelatine adhere to the glass when dry, ruining it. The top 
 of the sheet should be as level and smooth as the bottom. 
 Should air bubbles appear, remove them by touching with the 
 dampened finger. A little experience will determine the proper 
 consistency and temperature. The quantity in the formula 
 will cover about six hundred and seventy-five square inches. 
 Allow the frames to stand until the gelatine has set. This can be 
 determined by dampening the fmger and touching the surface. 
 It should be pliable but not sticky. Now place the frames in 
 the drying closet. It is best that the moistened air be carried 
 
112 DOUBLE WASHOUT GELATINE ENGRAVING. 
 
 outside of the building. If it is well constructed the sheets 
 should be sufficiently dried in forty-eight hours. If the drying 
 is carried on longer than four or five days, the quality will de*^ 
 teriorate and but little relief can be secured from the plates, 
 it is advisable to turn the plates end for end twice a day, so 
 that all parts will be equally exposed to the current of fresh 
 air. When the gelatine is dry, remove it from the glass. If 
 the above operations have been carefully performed, it should 
 part easily after a knife or spatula- has been run around the 
 edges of the frame. Should it be removed forcibly, it is liable 
 to take part of the glass with it, ruining the frame. In such 
 cases the cause is generally, solution which is too hot, improper 
 waxing of the glass, or too much moisture in the air passing 
 through the drying box. When the sheets are dried, trim off 
 the rough edges with a pair of wall-paperer's shears and pile 
 them up, placing a sheet of blotting paper between every two 
 sheets of gelatine, then place in the drawer of the work table 
 and put a flat board on the pile, sufficiently weighted to keep 
 the sheets from warping. The sheets should be about one- 
 sixteenth of an inch thick, perfectly smooth and even. When 
 ready to print, cut off a piece of gelatine a trifle larger than 
 your negative. Rub with talc the surface which was upon the 
 glass of the setting frame, dusting off the surplus powder with 
 a camel hair brush. Upon the glass of the printing frame lay 
 the negative with the film uppermost. Upon the negative place 
 the gelatine talced side down. Then lay the pad of felt above 
 it. In warm weather use the pressure pad, and finally force 
 down the back sufficiently to bring the gelatine in contact with 
 the negative. For coarse work, the frame may be exposed 
 directly to sunlight. Where the lines are close together, the 
 printing box should be fitted over its edges, and the opening 
 pointed towards the light. This will make the light strike per- 
 pendicularly and prevent the lines from becoming heavier or 
 running into each other. Where the color is evenly distributed, 
 as in type matter, the entire surface will require about the 
 same relief, and a plain exposure is sufficient. Where, how- 
 ever, it varies greatly, as in some wood engravings, a short 
 exposure would not give sufficient relief to the isolated lines, 
 while a long one would make the darker portions too heavy, as 
 even with the printing box some light would diffuse, causing 
 
DOUBLE WASHOUT GELATINE ENGRAVING. 113 
 
 the lines to run into each other. In work of this character it is 
 best to cover the glass of the printing frame immediately above 
 the darker portions of the copy, which in the negative are most 
 transparent. This can best be accomplished by applying with 
 a brush some opaque pigment, such as Venetian red, to which 
 is added a very small amount of gum arable dissolved in water. 
 After an exposure, which is judged to be about two-thirds of 
 that required for the lighter portions of the cut, the opaque 
 pigment is carefully cleaned off and another exposure made. 
 For subjects which require fine execution, and in which there 
 is great variance of color, this plan can be further elaborated. 
 Th'ree, four, or even a dozen different exposures, securing for 
 each part the proper amount of light. 
 
 It is impossible to name the length of time required for an 
 exposure. It will vary with the light, and with the composition 
 and age of the gelatine sheets. Generally five minutes is suffi- 
 cient, but it will vary from two to twenty minutes. When the 
 print'is finished, carry the frame into the operating room and 
 allow it to cool before removing the gelatine, otherwise there is 
 danger of spoiling the negative. Remove the back of the frame, 
 place the left hand upon the gelatine and, taking hold of one 
 corner with the right, gently raise it from the negative, in the 
 meantime sliding the left hand towards the opposite corner to 
 prevent its slipping. A little care will prevent the loss of the 
 negative. In practice, a number of prints are allowed to accu- 
 mulate, being placed in another drawer and weighted down as 
 before directed, to prevent their curling. When warm, they 
 are particularly liable to warp out of shape. 
 
 The washing out must be rapidly performed, and as the 
 manipulation is a delicate one, experience alone will render the 
 operator proficient. Fill a rubber tray with cold water and in 
 it lay a sheet of plate glass a trifle larger than the print. With 
 the left hand tip the gelatine under the surface with the un- 
 exposed side next the glass and, raising both sheets together, 
 press the water from between them. This operation must be 
 performed very rapidly, for should water be left between the 
 sheets, it would cause the gelatine to swell, and develop in the 
 subsequent manipulations a number of serious faults, such as 
 loss of fine details and curling of lines. Gelatine which has 
 been treated as directed is not nearly so liable to swell as 
 
t 
 
 114 DOUBLE WASHOUT GELATINE ENGRAVING. 
 
 Otherwise, nevertheless this tendency cannot be entirely over- 
 come. Lay the glass to which the gelatine is affixed on a block 
 of wood resting on the slides in the center of the sink, and pass 
 over the surface with some alcohol. This removes all moisture 
 or grease, and is particularly necessary when oil has been used 
 mstead of talc to prevent the negative from adhering. In the 
 meantime, the water for washing out should have been heated 
 about as hot as the hand can stand with comfort. Alongside 
 of It should be another basin of cold water. Grasp the wash- 
 out brush in your right hand, dip it in the hot water and pass 
 It firmly and freely with a circular motion over the entire sur- 
 face, frequently renewing the water until the required depth is 
 obtained without undermining the finer lines. If the work is 
 at all fine, the greater portion should have sufficient relief for 
 printmg. When this is obtained, remove the gelatine from the 
 glass and quickly dip into the cold water. Remove it as rapidly 
 as possible, shake and drain the superfluous moisture from it 
 and immerse it immediately in the tray which rests alongside 
 of the sink, and which is filled with wood alcohol. In a few 
 minutes it may be removed from this tray and placed in the 
 second one containing fresher alcohol which has not absorbed 
 water from frequent dippings. In this it should remain ten or 
 fifteen minutes. Now take the gelatine from the tray and allow 
 the surface to dry. If the work is in a hurry, evaporation may 
 be hastened by fanning. The gelatine is now ready for re- 
 mounting for the second washout. Select a piece of thin plate 
 glass a little larger than the cut and lay it upon the table 
 Paint the back of the gelatine with shellac. It is best to pre- 
 pare this yourself by soaking fresh unbleached shellac in pure 
 alcohol for several days until dissolved. Apply with a fine 
 camel hair brush in a thin even coating. When it becomes 
 tacky, place it against the glass. Lay a piece of blotting paper 
 over It and pass the squeegee roller from the center of the cut 
 to the outer edges, pressing out the superfluous shellac. Remove 
 the blotter, wipe the edges clean, and proceed with the next 
 cut. Place one above the other with a weight on top, and allow 
 the pile to dry as long as possible. In the meantime prepare 
 the blacking-in paste. For this, soak an ounce of fish alue or 
 white gelatine in eight or ten ounces of water, and" when 
 thoroughly swelled, dissolve in a water bath. Add from one 
 
DOUBLE WASHOUT GELATINE ENGRAVING. 115 
 
 to two drams of glycerine and a few drops of carbolic acid to 
 prevent its rotting. This is the stock bottle. Xw another bottle 
 have some Porto Rico molasses. It should be of good body, 
 not too thin, hi a convenient receptacle have some of the 
 finest ground lamp black. When everything is in readiness, 
 warm the gelatine in a water bath. Fill a shallow tin pan with 
 hot water and lay a piece of heavy sheet zinc above the bath. 
 The heat of the water will keep the zinc warm and prevent the 
 paste from setting. Pour some of the melted gelatine upon the 
 zinc, and alongside of it, a little of the molasses. The exact 
 proportions cannot be given— about two of the former and one 
 of the latter. With a small, steel spatula, grind and mix them 
 thoroughly together. Now take some lamp black and work it into 
 the mixture until the paste is soft, velvety and perfectly opaque. 
 As the ingredients vary greatly, nothing but experience can 
 determine their proportions. If too much gelatine is used, it is 
 liable to set too quickly, necessitating too much friction when 
 wiping it off. If there is too much molasses, it is liable to 
 remain soft and .wipe out from between the lines. If too little 
 lamp black has been used, the mass will not be opaque, but 
 will allow the light to penetrate it. If too much has been added, 
 the paste will lack cohesion and crack in drying, so that the 
 light will enter the fissures. When the mass is of the proper 
 consistency, apply it with the spatula to the surface of the 
 washed out cut, filling the spaces between the lines and remov- 
 ing the surplus with the same tool, taking care not to injure the 
 lines with its edge. The character of the work should be 
 plainly discernible through the thin coating which in places 
 adheres to the surface. Allow the paste to set, but not harden. 
 Take a damp cloth— portions of old linen or cotton clothing 
 without nap and worn soft are preferable— and, holding it in 
 the right hand, rub with the ball of the second finger only, keep- 
 ing the rest of the cloth from the surface with the first and third 
 fingers. Never wipe over the surface twice with the same spot 
 of cloth, and, while avoiding the removal of paste between the 
 lines, see that the surface is perfectly clean. It is best to give 
 a final cleaning with a piece of cloth which has not before been 
 used for the purpose. This can be used for the first rubbing of 
 the next plate. Immediately after use, throw the rags in a 
 basin of warm water, which will soften the paste so that they 
 
116 DOUBLE M^ASHOUT GELATINE ENGRAVING. 
 
 can be wrung out and used again. Should the large spaces be 
 unavoidably emptied, they can be filled in with a small brush 
 dipped into the warm paste. Hold the sheet up to the light, 
 and when an examination shows that the surface is perfectly 
 clean, and all the spaces between the lines are filled, lay the 
 sheet upon the printing board, and place this in such position 
 that the light strikes it at right angles to its surface. The 
 second exposure will be somewhat longer than the first, and 
 will vary from twenty to sixty minutes. After the second 
 printing take the plate to the sink, and with a brush used for 
 this purpose only, wash out the black paste. Then with the 
 heavy washout brush proceed to give the cut the required 
 relief, taking care not to continue the operation long enough to 
 undermine the lines or cause them to curl very much. This 
 operation will loosen the shellac, so that after plunging it in the 
 cold water the gelatine can easily be removed by passing the 
 spatula beneath it. It should then be quickly placed in the 
 alcohol as before. Do not allow it to remain long in the first 
 tray, otherwise it will swell by absorbing water with which the 
 alcohol has been diluted from previous plates. There is no 
 limit to the time at which it may be placed in the second tray, 
 which contains fresh and pure alcohol. The contents of the 
 second tray may be used for the first washing the following 
 day. When the sheet has hardend, remove it from the tray, 
 allow the alcohol to drain back into it, and wipe the back so as 
 to remove the shellac which still adheres. The cut is now ready 
 for mounting. For this purpose, zinc blanks are best adapted. 
 They should be perfectly flat and smooth, slightly larger than 
 the gelatine sheet, but need not be of high grade metal. Rub 
 the surface with the No. i sand paper until it is bright and 
 clean, coat the gelatine with a thin, even coat of shellac, and 
 fasten it to the surface of the zinc in the same way as it was 
 before attached to the glass. Be careful to avoid air bubbles 
 between the plates, as these may cause defective electrotypes. 
 Place a number of sheets above each other and weight down 
 until dry. This operation is usually performed at the close of 
 the day's work, so that the blocks may harden over night. If 
 all the manipulations have been carefully performed, the plates 
 will have plenty of relief and be hard and firm throughout. A 
 proof should now be taken and, if found correct, the plate sent 
 
DO UBLE WASHO UT GEL A TINE ENGRA VING. Ill 
 
 to the electrotyper, who proceeds to reproduce it in metal in the 
 usual manner. When a printing plate has been obtained, the 
 gelatine can be removed from the zinc, and the latter again 
 used after being polished, it is sometimes desirable to keep 
 the gelatine plates, in which case some care must be exercised, 
 as the gelatine is very brittle. The removal can be accom- 
 plished without breakage by applying a clean, flat spatula to 
 one edge and then another, and finally sliding it quickly between 
 the two sheets. As has before been noted, the gelatine pro- 
 cesses are comparatively difficult and, except in the hands of 
 an expert, uncertain. The most frequent difficulties are those 
 mentioned below. 
 
 CREEPING. 
 
 This is the technical name for the condition in which the 
 lines run into each other as if the light had penetrated through 
 the opaque parts of the negative. When washing out, the 
 lines will either be removed entirely or remain in a solid 
 black mass. This may be caused by the gelatine sheet not 
 being sufficiently dry, or too much glycerine having been added 
 to the mixture, but generally these faults will cause little trouble 
 unless accentuated by the usual cause — too much heat from 
 the sun. Very often this can be remedied by the use of the 
 water bag. If, however, this fails to remove the trouble, throw 
 away the gelatine and prepare a fresh batch. 
 
 CURLING OF LINES. 
 
 Noticeable while washing and always present to a slight 
 extent. Generally due to gelatine having been insufficiently 
 rotted, thereby requiring more time and longer brushing with 
 hot water to obtain the desired depth. It may also be caused 
 by the presence of too much glycerine or improperly dried 
 sheets. The alcohol bath will remedy it to a great extent, and 
 the addition to it of a little saturated solution of alum will 
 greatly facilitate matters. If, however, the gelatine is properly 
 prepared, alum should never be used. 
 
 INSOLUBILITY. 
 
 Caused by too long drying in a damp atmosphere, extreme 
 age of the gelatine, or exposure to light. It can be tested by 
 dampening a piece with tepid water and rubbing between the 
 fingers. It should melt away at this temperature without in 
 
118 DOUBLE WASHOUT GELATINE ENGRAVING. 
 
 the least swelling before dissolving. If it is flexible and clear, 
 and'shows this solubility, it should produce good cuts, it some- 
 times happens that the entire surface of the cut will not readily 
 yield to the washout brush. In such cases, sprinkle a little of 
 the fine pumice stone upon the surface and rub with the palm 
 of the hand until the fine polish has disappeared. Some en- 
 gravers prefer fine emery cloth, on which is rubbed a little 
 tallow to prevent its scratching. Before proceeding to wash 
 out, it should be rubbed with alcohol as heretofore directed. 
 
 GELATINE ADHERING TO NEGATIVE. 
 
 Often caused by the gelatine or negative not being thoroughly 
 dry. Look carefully to this and rub the surface of the former 
 with talc before placing them together. Another cause is, too 
 much heat during exposure. The water-bag will obviate this. 
 
CHAPTER XIV. 
 
 Single Washout Methods. 
 
 The complications involved in the operation of the method 
 described in the previous chapter have led to many efforts 
 towards simplification. Some have tried to overcome the 
 tedious rotting and its attending bad odors, others have labored 
 to perfect a method by which the necessary relief could be 
 obtained without the assistance of blacking-in paste, second 
 printing or hot water. Perhaps the most successful method is 
 that known in Europe as Leimtypy. From the following short 
 description it will be noted that in general outline it resembles 
 the double washout method, and wherever the operations are 
 not explicitly described it is to be understood that they are per- 
 formed in the same manner. Some of the recipes, such as for 
 cements, merely take the place of those previously described, 
 and may, if thought desirable, be substituted for them when 
 working the double washout process. 
 
 Soak three and one-half ounces of Nelson's amber gelatine 
 in seven ounces of water for five or six hours. Then place it 
 in a rice boiler and keep it at a temperature of from 140° to 
 1 50° until a tlocculent precipitate takes place, leaving the gela- 
 tine clear. This may take fifteen hours. Always keep the 
 vessel well covered, to prevent the formation of a skin on the 
 surface of the liquid. Cool the gelatine to about 100° and add 
 a little glycerine. The quantity will vary according to the 
 humidity of the atmosphere, and will generally be about five 
 drams in summer and three or four drams in winter. Too 
 much will make the printing plate soft. Too little will cause 
 concavity of the lines. Dissolve one ounce bichromate of potash 
 in sixteen ounces of water and add carbonate of ammonium 
 until all effervescence ceases. The quantity will probably be 
 about one ounce. This solution is to be kept in a stock bottle 
 
120 
 
 SINGLE WASHOUT METHODS. 
 
 and two drams of it are added to the above quantity of gelatine 
 under constant stirring. In another bottle dissolve fifty grains 
 of chromic acid in ten ounces of water. Add two ounces of 
 this solution to the gelatine bowl. Now beat the white of an 
 egg in one ounce of water, warm it to about ioo° and add to 
 the gelatine bowl. The emulsion is now to be strained through 
 the filtering cloth into the straining vessel or graduate. The 
 quantity before mentioned will be sufficient for covering a set- 
 ting frame ii x 14 inches. A temperature of 100° is best for 
 pouring, and the vessel or graduate should be heated so as not 
 to chill the gelatine below this point. When set, the frame 
 should be taken to the drying closet. The sheets should be dry 
 in fifteen or eighteen hours, but the best results will be obtained 
 if dried forty-eight hours, when the gelatine should still be flex- 
 ible enough not to break when bent. The exposure varies 
 according to the negative, light and character of the work. It 
 will generally take ten to thirty minutes. If an electrotype is 
 to be made, the gelatine can be mounted on the type metal 
 blank by means of ordinary glue, which should be tacky before 
 the film is laid on and squeegeed to its surface. If, however, 
 the gelatine is to be used for a printing plate, dissolve one part 
 of rubber in fifty parts of chloroform and add three parts of 
 mastic. Coat a piece of zinc thickly with this, solution, and 
 when dried heat it over the gas stove until the coating has 
 melted, and while still hot lay the gelatine upon it and squeegee 
 them tightly together. When the gelatine and mounting 
 metal are securely fastened, take the plate to the sink. In 
 the meantime, prepare a saturated solution of bichromate of 
 potash, and with a soft brush pass the cold liquid over the film. 
 In a few minutes the parts which have not been exposed to 
 light will commence to dissolve. It should not require more 
 than ten minutes rubbing to secure the necessary relief. When 
 the finer lines appear to weaken, wash thoroughly under the 
 tap, drain for a few moments and then lay in a dish of wood 
 alcohol. The relief will turn white and the wrinkled lines will 
 straigthen out. After laying in the alcohol for ten minutes take 
 out the plate and allow it to dry. If the relief is insufficient, 
 the washout operation may be repeated after an hour's time. 
 If it is intended to print directly from the plate, the large white 
 spaces are routed out with a chisel or routing tool, and the zinc 
 attached to a wood block by means of tacks. 
 
SINGLE WASHOUT METHODS. 
 
 121 
 
 Another method which is also productive of very good 
 results, and is quicker, is operated as follows : Place one pound 
 of Chaimer's granulated gelatine in a rice kettle and pour upon 
 it about three pints of water. After it has absorbed all the 
 water, which should be in about half an hour, keep the water 
 in the lower part of the kettle boiling for at least one hour, at 
 the end of which time the gelatine should have a slight odor of 
 decomposition. Take it from the fire and allow it to cool to 
 about 100°. In a porcelain mortar grind half or three-fourths of 
 an ounce carbonate of ammonium and add from three to four 
 ounces of water. Add from two drams to one-half an ounce of 
 stronger water ammonia. Then add, a small quantity at a 
 time, from one-half to three-fourths of an ounce of chromic acid. 
 After the effervescence has subsided, pour the solution in the 
 bowl while constantly stirring. The gelatine must be stirred 
 until all frothing subsides, when it should be of a yellowish 
 milky appearance. It will be noticed that this formula is not 
 exact. The amounts of the ingredients will vary with the 
 stage of decomposition, light, humidity, and other points which 
 tend to make all gelatine methods extremely difficult. Now 
 add about two ounces of glycerine and proceed in exactly the 
 same manner as in the double washout process, except that 
 the sheet is permanently mounted on the metal blank before 
 the first washout. Wash with warm water, using a stiff brush 
 for the first few rubs, and afterwards a finer one. Lay in the 
 alcohol tray and then allow to dry. The relief should be suffi- 
 cient for printing, although the large white spaces must be 
 routed out or built up in the mould by the electrotyper. 
 
CHAPTER XV. 
 
 Swelled Gelatine Engraving. 
 
 Engraving by this process is slower and more expensive 
 tiian zinc-etching, and, except for the reproduction of old en- 
 gravings where it is difficult to obtain dense negatives, it is not 
 recommended. Besides this, the manipulation is much more 
 delicate, and it requires more experience to obtain good results. 
 For these reasons it has become almost obsolete. 
 
 The negatives are made in exactly the same manner as 
 for the preceding methods, but are not stripped, the double 
 casting operation making the proof appear like the copy. In a 
 porcelain lined glue pot place half an ounce of Nelson's photo- 
 graphic gelatine No. i and add seven ounces distilled water. 
 Allow it to stand until the gelatine swells and becomes soft, 
 then heat until it is dissolved. Test frequently with the ther- 
 mometer, being careful that the temperature does not exceed 
 1 20° Fahr . When entirely dissolved, add thirty-two minims of a 
 saturated solution of bichromate of ammonia, stir thoroughly 
 and raise the temperature to 120°, keeping it at that heat for 
 five minutes, it is then filtered through muslin into a graduate 
 which has been warmed to the same degree of heat. In the 
 meantime a number of glass plates should have been carefully 
 cleaned. Pieces of plate glass about a quarter of an inch in 
 thickness, perfectly flat, free from scratches, and a little 
 larger than the negative, are best adapted to the purpose. 
 They must be carefully leveled by means of screws beneath 
 them, and warmed to the temperature of the solution. Enough 
 solution is poured upon each plate to cover it well without run- 
 ning over the edges. They are then removed to a dark room 
 or cupboard through which a current of air of 95° is made to 
 circulate until the gelatine is perfectly dry. The plates are 
 then ready for exposure, and will keep in good condition for 
 
■ SWELLED GELATINE ENGRAVING. 123 
 
 some time. The ordinary deep printing frame used by photo- 
 graphers answers very well for making the print. The nega- 
 tive and gelatine are placed face to face in the frame, and the 
 wedges forced in so as to bring them in contact. The exposure 
 in good sunlight will be about fifteen minutes, or in diffused 
 light, about one hour. When it is thought that the print is 
 sufficiently strong, it is removed from the frame and placed in a 
 shallow tray containing clear, cool water. The swelling begins 
 immediately, and its progress can be ascertained by feeling 
 with the finger tips. Considerable experience is required to 
 ascertain the proper length of time the swelling should be 
 allowed to continue. When it has reached a point where the 
 design is the depth of a four-ply card-board beneath the field, 
 the lines should still be flat upon the surface. Should the de- 
 velopment be allowed to proceed too far, the edges of the lines 
 will absorb water and in the finished design the surface of each 
 line will be convex, if not swelled sufficiently, the relief will 
 be shallow and the surface of the lines slightly concave. When 
 it is judged that the relief is sufficient, remove from the pan, 
 and after washing under the tap immediately place it in another 
 pan containing a saturated solution of iron sulphate. Allow it 
 to remain for three minutes, then remove and wash thoroughly. 
 Now lay it on a level slab and place iron bars, half an inch in 
 thickness, about one inch from the edges of the glass, and 
 parallel with them. In an earthen milk pan pour a little water 
 and add enough of the finest plaster of paris to make it the con- 
 sistency of syrup. Be sure to add enough plaster, as in case 
 the mixture is too thick water can be added without doing any 
 harm. A little salt is usually dissolved in the water, as it 
 makes the plaster set quickly and lessens its liability to crack 
 when casting. Work the mixture well with the 'hand. This 
 must be thoroughly yet rapidly done, otherwise the plaster will 
 set during the operation. Pour this mixture into the space 
 between the bars, being careful to avoid air bubbles, which 
 will make holes in the cast. When the plaster commences to 
 set, scrape with a straight edge, so that the surface is level 
 with the bearers. When set hard, run the edge of the knife 
 beneath one end, prying the glass and plate apart. The cast 
 is then trimmed and its edges beveled, leaving it an inch or two 
 wider than the design. Flow the cast several times with a 
 
124 SWELLED GELATINE ENGRAVING. 
 
 mixture prepared by adding one and one-lialf ounces silicate of 
 soda to twenty ounces of water and then wash well under the 
 tap. Lay it face upwards on the casting slab and place type 
 high bearers around the four sides. Plaster of paris is mixed 
 as before directed, poured into the space, and leveled even with 
 the bars. When hard, the two casts can easily be separated 
 with a spatula. The metal cast is made in an electrotypers' 
 furnace provided with a casting pan (Fig. 60) which by means 
 
 Fig. 60. 
 
 of a crane can be swung into the furnace or into the adjoining 
 cooling box. The pan is heated in the metal and placed on a 
 leveling block alongside the furnace. in the pan is placed 
 the float, which has also been heated. On this are arranged the 
 plaster casts face downwards. There should be enough to fill 
 the entire pan, otherwise blanks must be used to prevent the 
 contents from floating around. The lid is now attached and 
 securely fastened, and by means of the crane the pan is swung 
 in the metal, it is allowed to float on the surface for about five 
 minutes, or until thoroughly heated, when it is lowered slowly 
 until completely submerged, and held there until the splashing 
 and bubbling caused by the escaping steam ceases. It is then 
 gently raised to the surface and swung into the cooling box, 
 the surface of which is covered with a thin layer of water. 
 The metal will shrink as it cools, and the deficiency should be 
 supplied with the ladle. Cold metal will make defective casts. 
 Cooling it too rapidly will cause cracks. When cold, the pan is 
 taken from the trough and laid on a strong bench or block. 
 The iron clamp is loosened and the cover pried off with a cold- 
 chisel. The cast, which appears a solid lump of metal, is placed 
 so that it lies in the same position as when in the pan, and the 
 corners are struck with a heavy hammer until it separates in 
 two parts, the molds and plate remaining attached to the metal. 
 The plaster which adheres to the face of the cast may be re- 
 
SWELLED GELATINE ENGRAVING. 
 
 125 
 
 moved by soaking in a trough of water. Casts are of an 
 irregular thickness, and after being sawn to size are placed in 
 an electrotypers' roughing machine and cut to the correct gauge. 
 If all the operations have been carefully performed, the design 
 will appear in low relief. Except where the lines are very close 
 together, this will be insufficient for printing purposes. The 
 large spaces must be removed in the routing machine, and the 
 small ones carefully worked over with a graver. The block is 
 then mounted on wood, when it is ready for use, but the metal 
 being comparatively soft, it is always best to first make an 
 electrotype. 
 
INDEX. 
 
 /\cid, nitric 63 
 
 Acid, strength for etching 63-64 
 
 Acid pump 98 
 
 Albumen, adding to gelatine 120 
 
 Albumen solution for printing on 
 
 zinc • 52 
 
 Alcohol 27 
 
 Alcohol in bath 38 
 
 Alcohol trays 107 
 
 Alum 117 
 
 Arrangement of shop 13 
 
 Asphaltum, printing with 85 
 
 Asphaltum varnish 63 
 
 Bag, pressure 108 
 
 Bath for graining zinc 52 
 
 Bath, the silver 29 
 
 Bath, alcohol in 38 
 
 B ath , c 0 rrecti n g th e 4 1 ? 45 
 
 Bath, iodizing the 30 
 
 Bath, new 41 
 
 Bath, organic matter in 45 
 
 Bath, over-iodized 44 
 
 Bath, scum on 44 
 
 Bath dipper 29 
 
 Bath holder 29 
 
 Bichromate of ammonia 52 
 
 Bichromate potassium- no, 1 19-120 
 
 Bitumen of Judea 85 
 
 Blacking in paste 115 
 
 Bleaching silver prints 99 
 
 Block, finishing the 73 
 
 Block, routing the 73 
 
 Block, straightening the 48 
 
 Blocking nails 78 
 
 Blocking plate 77 
 
 Blocking wood 77 
 
 Board, copy 18 
 
 Board, printing 108 
 
 Bookwork 103 
 
 Borders, to make 96 
 
 Box, drying, for washout gela- 
 tine 104 
 
 Box, powdering 23, 61, 100 
 
 Box, printing 108 
 
 Box, pumice stone 108 
 
 Box, rotting 108 
 
 Box, talc 108 
 
 Brushes, etching 63 
 
 Brushes, powdering 61 
 
 Brushes, rubber bound 63 
 
 Brushes, washout 106 
 
 Callipers 50 
 
 Camera, copying 20 
 
 Camera, enlarging and reducing 21 
 Camera, focusing for negative- - 36 
 Camera, marking for reductions 95 
 
 Camera stand I9 
 
 Camera swings 16 
 
 Cast of plaster for swelled gela- 
 tine engraving 123 
 
 Cast, metal, for swelled gelatinei24 
 
 Castor oil 32, 55, 60 
 
 Celluloid, printing on zinc with 40 
 Cement for attaching gelatine to 
 
 metal -.116-120 
 
 Charcoal, polishing 51 
 
 Chemicals, preparation of 25 
 
 Chemicals, selection of 26 
 
 Circular saw 74 
 
 Collodion method, advantages of 25 
 Collodion, flowing glass with-- 34 
 
 Collodion, new 28, 41-42 
 
 Collodion, preparation of 27 
 
128 
 
 INDEX. 
 
 Collodion, stripping 32 
 
 Collodion, too strongly salted-- 44 
 
 Collodion, thick 28 
 
 Collodion, uneven films of 43 
 
 Collodion, unsettled 43 
 
 Color work, French method 102 
 
 Color work ingrain 99 
 
 Cooling slab 23, 62 
 
 Composition rollers 56 
 
 Copper, etching 67 
 
 Copper, half-tone on 93 
 
 Copper, to coat zinc with 97 
 
 Copy-board i8 
 
 Copying Camera 20 
 
 Cotton, filtering 26 
 
 Cotton, soluble, for collodion-^- 27 
 
 Cover for roller 56 
 
 Covers for roller handles 56 
 
 Creeping of gelatine m, 117 
 
 Curling of lines 117 
 
 Cuts in grain 99 
 
 Cuts, to reverse 96 
 
 Cutting zinc 47 
 
 Dampness, effect on zinc 97 
 
 Dark room, care of 41 
 
 Dark room for negatives 21 
 
 Dark room for printing on zinc 23 
 
 Developer 30 
 
 Developer, too strong 42-44 
 
 Developing the negative 37 
 
 Development, retarding 38 
 
 Dipper, bath 29 
 
 Dishes for rotting gelatine 106 
 
 Dishes, pouring 106 
 
 Double washout gelatine en- 
 graving 103 
 
 Dragon's blood 61 
 
 Drawing on zinc 98 
 
 Drawing, to reverse 96 
 
 Drying box for washout gelatine, 104 
 Dry plate photography, objec- 
 tions to 2^ 
 
 Z,-) 
 
 Dust on film 43 
 
 Dusting box for Mezzotype 100 
 
 E lectrotype 84 
 
 Enlarging and reducing camera- 21 
 
 Equipment of shop 13 
 
 Etch, the finishing 66 
 
 Etch, the first 63 
 
 Etch, the second 64 
 
 Etch, the third 65 
 
 Etcher's oven 62 
 
 Etching brushes 63 
 
 Etching ink No. I 57 
 
 Etching ink No. 2 66-69 
 
 Etching copper 67 
 
 Etching, finishing the 73 
 
 Etching half-tone 92 
 
 Etching, mounting the 75 
 
 Etching powder 61 
 
 Etching, retouching the 82 
 
 Etching room 23 
 
 Etching, routing the 73 
 
 Etching tub 63 
 
 Etching zinc 51 
 
 Ether 2? 
 
 Exposing negative 37, 44 
 
 Film, clouded or mottled 44 
 
 Film, dust on 43 
 
 Film, imperfect 28 
 
 Film leaving glass 33 
 
 Film, preserving 40 
 
 Film, ridged 45 
 
 Film, stripping the 39 
 
 Film, uneven 43 
 
 Filtering 26 
 
 Filtering cloth 106 
 
 Finger stains, to remove 98 
 
 Fingertips 65 
 
 Finishing the block 73 
 
 Finishing plate 77 
 
 Fixing the negative 38 
 
 Fixing solution 30 
 
 Fixing solution, to keep in order 38 
 Flowing glass with collodion--- 34 
 
 Focusing 36, 43 
 
 Fog caused by new collodion--- 28 
 
 Fog in negatives 38, 41 
 
 Frame for printing on zinc---23, 53 
 Frames, printing, for gelatine 
 
 swell 123 
 
 Frames, printing, for gelatine 
 
 washout 107 
 
INDEX. 
 
 129 
 
 Frames, setting, for washout 
 
 gelatine --105 
 
 French color process 102 
 
 Funnels 26 
 
 Gelatine adhering to glass, 
 
 cause of 112 
 
 Gelatine adhering to negative- - 118 
 
 Gelatine, creeping of 117 
 
 Gelatine, curling of 117 
 
 Gelatine, double washout 103 
 
 Gelatine, insolubility of 117 
 
 Gelatine, to mount for electro- 
 typing 116, 120 
 
 Gelatine, to print upon 113 
 
 Gelatine, to rot no, ny 
 
 Gelatine, to sensitize for swelled 
 
 gelatine 122 
 
 Gelatine, to sensitize for washout 
 
 gelatine no, iig, 121 
 
 Gelatine, single washout ng 
 
 Gelatine swell engraving 122 
 
 Gelatine, washing out n3, 120 
 
 Gelatine washout engraving, 
 
 work room for 104 
 
 Glass, cleaning 33 
 
 Glass, flowing with collodion-- 34 
 
 Glass for printing frames 54 
 
 Glass, negative 33 
 
 Glass, plate 40 
 
 Glass, stripping 40 
 
 Glycerine for washout gela- 
 tine ni, n7, i\g 
 
 Graduates 26 
 
 Graining zinc 52 
 
 Gravers for zinc 82 
 
 Gum arable, to test 69 
 
 Gumming up 69 
 
 Gum solution 69 
 
 Gun cotton 27 
 
 Half-tone 88 
 
 Half-tone, borders for 93 
 
 Half-tone, copper 93 
 
 Half-tone, darkening parts 93 
 
 Half-tone, definition of term 9 
 
 Half-tone, etching 92 
 
 Half-tone kits 90 
 
 Half-tone, lightening parts 93 
 
 Half-tone, negatives for 91 
 
 Half-tone, print on metal for 92 
 
 Half-tone, roulette for 93 
 
 Half-tone, screen plates for 89 
 
 Half-tone, spots in 93 
 
 Half-tone, whites in 92 
 
 Hammer 50 
 
 Handle covers for rollers 56 
 
 Historical sketch 7 
 
 Holder, bath 29 
 
 Holder, plate 20, 37 
 
 Hydrometer, silver ' 26 
 
 Ink for rolling up prints 56 
 
 Ink, lithographic transfer 56 
 
 Ink, No. I etching 57 
 
 Ink, No. 2 etching 66, 69 
 
 Ink slab 23, 56 
 
 Intensifiers 31 
 
 Intensifying the negative 38 
 
 Intensity of negative, varying-- 43 
 
 Iodine, tincture of 28 
 
 Iodizing the silver bath 30 
 
 Iron, perchloride of 67 
 
 K-its for half-tone 90 
 
 Lamp, darkroom 22 
 
 Left-handed cuts 39 
 
 Lens 19 
 
 Leveling table 106 
 
 Lines, curling of n7 
 
 Lines in negative 44 
 
 Lines, protecting by gumming up 69 
 Lines, protecting by powdering 
 
 four times 64 
 
 Lithographer's roller, rough 69 
 
 Lithographer's roller, smooth -- 55 
 Lithographer's roller, to prepare 55 
 
 iVlachinery, care of 81 
 
 Meisenbach process for half-tone 88 
 
 Melting powder on plate 61 
 
 Metal, mounting on 81 
 
 Mezzotype process 99 
 
130 
 
 INDEX. 
 
 Middle Varnish 55 
 
 Mirror for reversing negatives-- 96 
 
 Mounting nails 78, 82 
 
 Mounting wood 75 
 
 Nails for mounting 78, 82 
 
 Negative, clearing the 39 
 
 Negative, clouded 44 
 
 Negative collodion, preparation of 27 
 
 Negative, dark room for 21 
 
 Negative, defective--! 41 
 
 Negative developer 30 
 
 Negative, developing the 37 
 
 Negative, dust on 43 
 
 Negative, exposing 37 
 
 Negative, fixing the 38 
 
 Negative, focusing for 36 
 
 Negative, foggy 38, 41 
 
 Negative glass 33 
 
 Negative, half-tone 91 
 
 Negative, indistinct--- 43 
 
 Negative, making 33 
 
 Negative, intensifying the 38 
 
 Negative, lines on 44 
 
 Negative, mottled 44 
 
 Negative, over-developed 38, 43 
 
 Negative, over-exposed 38, 42 
 
 Negative, pinholes in 43 
 
 Negative, ridged 45 
 
 Negative, reversed 96 
 
 Negative, sensitizing plate for-- 35 
 
 Negative, spots in 43 
 
 Negative, stains in 42 
 
 Negative, streaks in 42 
 
 Negative, stripping the 39 
 
 Negative, under-developed- --38, 43 
 
 Negative, under-exposed 38 
 
 Negative, varying intensity of-- 43 
 
 Nitrate of silver 29 
 
 Nitric acid 6^ 
 
 Nomenclature 7 
 
 Oil, castor 32, 55, 60 
 
 Organic matter in silver bath-- 45 
 
 Oven, etcher's 62 
 
 Over-development 38, 43 
 
 Over-exposure 38, 42 
 
 Paste, blacking in 115 
 
 Perchloride of iron 67 
 
 Photo-engraving, definition of 
 
 term g 
 
 Photograph, bleaching 99 
 
 Photographing room 13 
 
 Pinholes in negative 43 
 
 Plans for shop 13 
 
 Plaster of paris cast 123 
 
 Plate, sensitizing for negative-. 35 
 
 Plate glass 40 
 
 Plate holder 20, 37 
 
 Pliers, wide nose 62 
 
 Polishing charcoal 51 
 
 Polishing zinc 49 
 
 Pouring dish 106 
 
 Powder, etching 61 
 
 Powder for mezzotype process-- 100 
 
 Powdering 61 
 
 Powdering box 23, 61 
 
 Powdering box for mezzotype 
 
 process 100 
 
 Powdering four times 64 
 
 Powdering brush 61 
 
 Powdering the plate after the 
 
 first etch 64 
 
 Preparations, compounding of-- 25 
 
 Pressure bag 108 
 
 Printing board 108 
 
 Printing boxes 108 
 
 Printing frame for gelatine wash- 
 out 107 
 
 Printing frame for swelled gela- 
 tine 123 
 
 Printing frame for zinc 53 
 
 Printing frame, glass for 54 
 
 Printing on zinc without frame- 59 
 
 Print on metal for half-tone 92 
 
 Print on zinc 47 
 
 Print on zinc, celluloid for 40 
 
 Print on zinc, dark room for 23 
 
 Print on zinc, developing 57 
 
 Print on zinc, frame for ,23 
 
 Print on zinc, imperfect 58 
 
 Print on zinc, ink for rolling up. 56 
 
 Print on zinc, painting in 59 
 
 Print on zinc, retouching 58 
 
INDEX. 
 
 131 
 
 Print on zinc, sensitizing solu- 
 tion for 52, 85 
 
 Prints, silver, to make and bleach 99 
 Prisms for reversing negatives- 96 
 
 Proof, to make 82 
 
 Protecting lines by gumming up 69 
 Protecting lines by powdering 
 
 four times 64 
 
 Pumice stone 49, 118 
 
 Pumice stone box 108 
 
 Punch 50 
 
 Reflectors 43 
 
 Reversing color of copy 95 
 
 Reversing drawings 96 
 
 Reversing mirrors 96 
 
 Roller, composition 56 
 
 Roller cover 56 
 
 Roller for prints on zinc 55 
 
 Roller, lithographer's, to prepare 55 
 
 Roller, rough lithographic 69 
 
 Roller, rubber 56 
 
 Roller, smooth lithographic 55 
 
 Roller, squeegee 107 
 
 Rotting box 108 
 
 Rotting dishes 106 
 
 Roulette for half-tone 93 
 
 Roulette for line work 83 
 
 Router cutters for metal 74 
 
 Router cutters for zinc 73 
 
 Routing 73 
 
 Rubber rollers 56 
 
 Rubber stripping solution 31 
 
 Saw, circular 74 
 
 Scales' 25 
 
 Scotch stone 50 
 
 Scraper, zinc 51 
 
 Screen plates for half-tone 89 
 
 Sensitizing plate for negative-35, 36 
 Sensitizing solution for printing 
 
 on zinc 52, 85 
 
 Sensitizing zinc 53 
 
 Setting frames for washout gela- 
 tine 105 
 
 Shafting 73 
 
 Shaver 82 
 
 Shellac 114 
 
 Shootboard 78 
 
 Shop, arrangement and equip- 
 ment of 13 
 
 Silver bath 29 
 
 Silver bath, correcting the ---41, 45 
 
 Silver bath, iodizing the 30 
 
 Silver bath, organic matter in -- 45 
 
 Silver bath, over-iodized 44 
 
 Silver bath, scum on 44 
 
 Silver hydrometer 26 
 
 Silver, nitrate of 29 
 
 Silver prints, to make and bleach 99 
 
 Silver, saving 95 
 
 Single washout methods 119 
 
 Sketch, historical 7 
 
 Skylight 15 
 
 Slab, cooling 23, 62 
 
 Slab, ink 23 
 
 Smasher hammer 5° 
 
 Soluble cotton 27 
 
 Solution, collodion stripping 32, 
 
 Solution for clearing negatives-- 31 
 
 Solution for fixing negatives 30 
 
 Solution for sensitizing zinc 52 
 
 Solution, rubber stripping 31 
 
 Spatulas 107 
 
 Sponge, to prepare for gumming 69 
 
 Spots in negatives 43 
 
 Squeegee 4° 
 
 Squeegee roller 107 
 
 Stains in negatives 43 
 
 Stains, to remove from fingers-- 98 
 
 Stand, camera 19 
 
 Stone, pumice 49 
 
 Stone, Scotch 5° 
 
 Staightening block 48 
 
 Straining cloth 106 
 
 Stripping collodion 32 
 
 Stripping glass 4° 
 
 Stripping solutions 31 
 
 Stripping the negative film 39 
 
 Swelled gelatine engraving 122 
 
 Swing, camera 16 
 
 Table for cutting zine 48 
 
 Table, leveling, for washout 
 
 gelatine 106 
 
 Talc box 108 
 
132 
 
 INDEX. 
 
 Tank, etching ; 63 
 
 Tincture of iodine 28 
 
 Tint plates for color work 100 
 
 Transparancy, to make 95 
 
 Trays, alcohol 107 
 
 Trimmer 79 
 
 Tub, etching 63 
 
 Tuche 98 
 
 Turpentine 57 
 
 LJnder-development 38, 43 
 
 Under-exposure 38 
 
 Varnish, asphaltum 63 
 
 Varnish, heavy 56 
 
 Varnish, middle 55 
 
 Washout brushes 106 
 
 Washing out gelatine 113, 120 
 
 Washout gelatineengraving 103, 119 
 
 Wastes, saving the 95 
 
 Water, impure 42 
 
 Waxing setting frames no 
 
 Wet plate method of photogra- 
 phy, advantages of 25 
 
 Whirler 86 
 
 White on black, to make a cut-- 95 
 Wood for mounting 75 
 
 Zinc, buffing 51 
 
 Zinc callipers 50 
 
 Zinc, cutting 47 
 
 Zinc, dark room for printing on- 23 
 
 Zinc, drawing on gg 
 
 Zinc, engraving 83 
 
 Zinc, etching 
 
 Zinc etching, cleaning 66 
 
 Zinc etching, definition of term- 8 
 Zinc, frame for printing on---23, 53 
 
 Zinc, grained, for drawing 98 
 
 Zinc, graining 52 
 
 Zinc hook 48 
 
 Zinc, printing on, with celluloid- 40 
 
 Zinc, print on 47 
 
 Zinc, print on, developing 57 
 
 Zinc, print on, imperfect 58 
 
 Zinc, print on, ink for rolling up 56 
 
 Zinc, print on, retouching 58 
 
 Zinc, router cutters for 73 
 
 Zinc scraper 51 
 
 Zinc, size of 47 
 
 Zinc, -sensitizing 53 
 
 Zinc, sensitizing solution for 
 
 printing on 52, 85 
 
 Zinc, straightening 48 
 
 Zinc, tests for quality of 47 
 
 Zinc, thickness of 47 
 
 Zinc, to coat with copper 97 
 
 Zinc, to clean before sensitizing- 52 
 Zinc, to print on without a frame 59 
 Zinc, to protect from dampness- 97 
 Zinc, to remove holes from 50 
 
3^^^ 8