The 
 
 Chemistry and Technology 
 of Printing Inks 
 
 BY 
 
 NORMAN UNDERWOOD 
 
 CHIEF OF THE INK-MAKING DIVISION, BUREAU OF ENGRAVING AND 
 PRINTING, UNITED STATES TREASURY DEPARTMENT 
 
 AND 
 
 THOMAS V. SULLIVAN 
 
 ASSISTANT CHIEF OF THE INK-MAKING DIVISION, BUREAU OF ENGRAVING 
 AND PRINTING, UNITED STATES TREASURY DEPARTMENT 
 
 Illustrated 
 
 NEW YORK 
 
 D. VAN NOSTRAND COMPANY 
 25 PARK PLACE 
 
COPYRIGHT, IQIS, BY 
 D. VAN NOSTRAND COMPANY 
 
PREFACE 
 
 THE authors have endeavored in the preparation of this 
 volume to prepare a concise work on the chemistry and 
 methods of manufacture of one of the most important 
 materials of the present day. 
 
 They have attempted to give in a brief and practical 
 but yet scientifically correct manner the many facts con- 
 cerning the raw materials and finished products used in 
 this industry which they have collected during a number 
 of years of laboratory work and manufacturing experience. 
 
 Obsolete methods and materials which have been found 
 to have no value in the art on account of modern improve- 
 ments or excessive cost have been omitted. 
 
 The attempt has been made to present the most recent 
 methods of manufacture and a description of the materials 
 which have been found useful in the art in a clear and con- 
 cise manner. The authors have spent a great deal of time 
 on the form and style of the book in the hope that it may 
 prove valuable and serviceable to the many workers in this 
 art. 
 
 WASHINGTON, D. C. N. U. 
 
 Sept. i, 1914. T. V. S. 
 
 331006 
 
CONTENTS 
 
 PAGE 
 
 INTRODUCTION i 
 
 PART ONE 
 
 TESTING OF MATERIALS 
 
 LABORATORY APPARATUS 15 
 
 METHODS OF ANALYSIS 22 
 
 PHYSICAL TESTS or PIGMENTS 36 
 
 PART TWO 
 MANUFACTURE AND PROPERTIES OF INK-MAKING MATERIALS 
 
 REDS 39 
 
 BLUES 41 
 
 YELLOWS 45 
 
 GREENS 53 
 
 ORANGES 55 
 
 RUSSETS 60 
 
 CITRINES 62 
 
 BLACKS 63 
 
 DlLUTENTS 74 
 
 BASES 78 
 
 ORGANIC LAKES 84 
 
 OILS 88 
 
 TYPOGRAPHIC VARNISHES 98 
 
 REDUCERS 100 
 
 DRIERS 102 
 
 PART THREE 
 THE MANUFACTURE OF PRINTING INK 
 
 GENERAL CONSIDERATIONS 104 
 
 EXPLANATION OF TERMS no 
 
 PRINTING INKS 112 
 
 PLATE INKS 112 
 
 TYPOGRAPHIC INKS 120 
 
 DEFECTS OF INKS AND THEIR REMEDIES 127 
 
 INDEX 135 
 
INTRODUCTION 
 
 THE manufacture of printing inks today, does not, 
 as would appear at first glance, consist merely in the 
 combining together of pigments, driers and vehicles in 
 certain proportions. 
 
 Besides the mere combination of ingredients, the qual- 
 ity, suitability and characteristics of these materials 
 must be considered in order to arrive at the combina- 
 tion that will be both chemically and physically adapted 
 to give the best results. 
 
 In order to determine the quality, suitability and char- 
 acter of the ingredients that go into printing inks, it is 
 necessary to have some knowledge of the constitution 
 and methods of manufacture of these materials, and to 
 be able by chemical analysis and physical tests to deter- 
 mine whether these materials have been properly made 
 and whether they are by nature fitted for the work they 
 will be called upon to do. 
 
 If the characteristics and properties of all the raw 
 materials employed in the printing-ink industry are well 
 understood and one has a comprehensive technical knowl- 
 edge of the results to be obtained by the use of a cer- 
 tain ink, combinations can be worked out that will give 
 simple formulas and ones that will give the very best 
 working inks for any given purpose, with the added ad- 
 vantage that they will be easy to manipulate to meet 
 any unexpected conditions that may arise in printing. 
 
2 INTRODUCTION 
 
 With these facts in mind, we have divided this book 
 into three parts: namely, methods of testing raw ma- 
 terials; the manufacture and properties of pigments and 
 varnishes; and the manufacture of inks. 
 
 We have not devoted any space to the chemical analy- 
 sis of finished inks as there is nothing to be learned by 
 such an analysis, except, that in some cases it may give 
 one thoroughly conversant with inks some slight sugges- 
 tion in regard to the duplication of an ink. A general 
 chemical analysis will not, however, convey any idea of the 
 essential composition of the ink. It will show the percent- 
 age of oil to pigment, whether the oil is linseed, rosin, or 
 petroleum oil, and in a general way what the pigment is, 
 but it shows practically nothing concerning the physical 
 condition of the materials before manufacture or how they 
 were combined; and unless the chemist has a practical 
 knowledge of ink making, it does not show even this much. 
 
 For example, an analysis may show the presence of 
 linseed oil, but it will not show the consistency of the 
 oil used in making the ink nor whether two or three dif- 
 ferent consistencies were used. Neither will it show if 
 the oil was combined as a gum varnish, in a drier, or 
 whether it was burnt or boiled. It will not show whether 
 the drier used was a paste drier, a japan drier, a drier 
 merely added dry when the ink was made or incorporated 
 into the oil at the tune of burning or boiling, or whether 
 it was introduced in the form of a metallic soap. It 
 may show the presence of a mineral oil, but it will not 
 show whether the oil is petrolatum, paraffine oil or kero- 
 sene. If aluminum is found, it will not show whether 
 it was added as a base to the ink, or whether it was part 
 of a lake pigment that was used. 
 
 
INTRODUCTION 3 
 
 The following analyses as reported by 'analysts not 
 familiar with the manufacture of inks together with their 
 actual composition will be of interest in this regard. 
 
 ANALYSIS OF AN ENGRAVING BLACK 
 
 Oil (partly boiled linseed) 30.31 
 
 Carbon 38.90 
 
 Silica and insoluble silicates 9.50 
 
 Calcium Phosphate 9.04 
 
 Calcium Sulphate 2.82 
 
 Calcium Carbonate 1.83 
 
 Oxide Iron 26 
 
 Berlin Blue 7.34 
 
 Items marked * represent 62.35% of common spent bone black. 
 
 Now this ink was actually composed of the following 
 materials : 
 
 Bone Black 37 % 
 
 Vine Black .16 
 
 Prussian Blue 7 
 
 Paste Drier 10 
 
 Strong Burnt Plate oil 4 
 
 Medium Burnt Plate oil 26 
 
 In this ink the vine black and strong plate oil are es- 
 sential for the proper color and working properties, yet 
 their presence is not shown by the analysis and could 
 not be deduced from it. 
 
 ANALYSIS OF A BLACK TYPOGRAPHICAL INK 
 
 Pigment 20 % 
 
 Oil 80 " 
 
 Oil 
 
 Rosin oil 60 " 
 
 Rosin 22 
 
 Linseed Varnish 18 " 
 
 Pigment 
 
 Ash and oil driers 2.5 " 
 
 Prussian Blue 3.9 " 
 
 Carbon, etc 93.6 " 
 
4 INTRODUCTION 
 
 This ink actually contained only about 4 per cent of 
 linseed oil, the basic vehicle being a varnish made from 
 paraffine oil and rosin, the rest of the vehicle consisting 
 of about 15 per cent second run rosin oil and about 20 
 per cent of a long varnish made from paraffine oil, asphal- 
 tum, wood tar and kerosene with a small amount of japan 
 drier. An ink made from the formula as shown by the 
 analysis would not make an ink that was suitable for the 
 purpose this ink was intended, that is for a news ink run 
 on a high-speed web press on news paper. 
 
 In our work on printing inks and ink-making materi- 
 als, we have found that the simpler a formula is, the less 
 trouble one will have with the ink, and in the event of 
 trouble, it will be easier to identify the cause and remedy 
 the defect. There has always been a tendency in the 
 printing-ink business, as conducted in a practical way, 
 without reference to the technical side of the industry, 
 to have formulas for inks, particularly those for special 
 purposes, as complicated as possible. This is due mainly 
 to the fact that these inks were the result of long "rule 
 of thumb" experiments, in which the different materials 
 were added until the combination sought for was ob- 
 tained, and partly to the fact that every ink maker and 
 printer has a number of trade secrets which are con- 
 sidered to be of great value in making inks work properly. 
 The value, however, of these secrets is in most cases 
 doubtful. 
 
 In the chapter on the manufacture of printing inks, we 
 have not given any working formulas, since the proper- 
 ties of materials from different sources are quite variable 
 and the conditions under which inks are used are liable 
 to be very different. It would therefore be impossible 
 
INTRODUCTION 5 
 
 to give exact figures that would be of any service and 
 we have only given general formulas for the composition 
 of the usual classes of inks, and an outline of the de- 
 fects liable to occur and the remedies that we have found 
 effective. 
 
 The information in this book represents a great deal of 
 research, both in the laboratory, and in the works, noth- 
 ing being taken for granted, and no statement is made 
 that has not actually been proved in practice. In order 
 to avoid useless discussion and to make the work sim- 
 pler, we have only mentioned those things which we have 
 found to be the best of their line. There are a great 
 many materials and methods used both by ink manufac- 
 turers and printers, to accomplish certain things which 
 we have tried, but have not mentioned, either, because 
 they did not accomplish the result claimed for them, or 
 because we found something else would do so better or 
 in a simpler way. 
 
 The pigments to be used for the manufacture of print- 
 ing inks must be looked at from a different standpoint 
 and judged by different standards than those to be used 
 in making paints. While a great many pigments of the 
 same chemical composition are common to both indus- 
 tries, the fact that one of them under certain conditions 
 is acceptable as a material for paint, cannot be taken as 
 an indication that it will be equally acceptable when 
 ground into a printing ink. There are a great many pig- 
 ments, that, while they are available for use as paints, 
 cannot under any circumstances be used for ink and a 
 number of very satisfactory ink-making pigments are not, 
 for various reasons, adaptable for use in making paints. 
 
 The chief source of these differences can be easily ex- 
 
6 INTRODUCTION 
 
 plained by the ultimate use of the two products, as it 
 can readily be seen, that the materials which are used 
 to make a product to be applied with a brush, in a thick 
 layer, and whose chief function is covering, can differ 
 widely in properties from those that are to be used in a 
 product which is put on in the thinnest possible layer and 
 which has many other functions to perform besides that 
 of covering surface. 
 
 While a pigment for use in paint must be judged, to a 
 certain extent, by its color strength, its body, its fineness 
 of grinding, its miscibility with other pigments and the 
 usual vehicles, its durability and weathering properties 
 and its fastness to light, a pigment for use in printing 
 ink must be examined into for all of these properties in 
 the minutest way; and it must also have certain other 
 characteristics not necessary, and in some cases not de- 
 sirable in paint pigments. For example, there are pig- 
 ments that, when mixed with a large quantity of oil and 
 thinned with turpentine, work well under a brush but 
 show shortness and lack of viscosity, when made up to 
 the consistency of ink, and which will not distribute at 
 all on the press. Venetian red, an admirable paint pig- 
 ment, is, on account of its hard, gritty nature, of prac- 
 tically no value as an ink-making pigment. A large 
 number of aniline lakes, on account of their transparency 
 and lack of covering power, are not used in paints, but 
 for this very reason are desirable for use in certain kinds 
 of printing inks. 
 
 In the following chapters we will take up these pig- 
 ments and discuss them only from the standpoint of their 
 availability for use in printing inks, making no mention 
 of those pigments not suitable for this work. 
 
INTRODUCTION 7 
 
 Explanation of the Terms that are to be Used. As 
 
 many of the technical terms used to describe the proper- 
 ties of pigments and inks are frequently used in a con- 
 fusing and indefinite way, the following explanation of 
 the meaning of the terms hereafter to be employed, will 
 help to eliminate any misunderstanding in their use. 
 
 Hue. As the normal spectrum colors merge into each 
 other, we have a condition where one color has a slight 
 mixture of the other in it and this slight mixture gives 
 to the predominating color what is called a hue. Thus 
 if we have red slightly tinged with violet, this is called 
 red of violet hue. On the other hand if we have a violet 
 merging into red, that is, if a slight amount of red tinges 
 the violet the result is a violet of red hue. Green in 
 passing into blue gives us first a green of blue hue, and 
 then a blue of green hue, as first the one, and, then the 
 other predominates. 
 
 In speaking of pigments this can be carried further, 
 to mean that, when two pigments are mixed to produce 
 a new color and the color of one pigment predominates 
 in the mixture, the resultant color will have the hue of 
 the predominating pigment. Thus when yellow pre- 
 dominates in a mixture of yellow and blue, we get a green 
 of yellow hue and if the blue predominates, we get a 
 green of blue hue. 
 
 Tint. When a normal spectrum color or hue of that 
 color is mixed with white, we get a gradation of that 
 color lighter in appearance and this is called a tint of 
 the original color. In speaking of pigments a tint means 
 a pigment lightened by the admixture of white. 
 
 Shade. When a normal spectrum color, or one of 
 its hues, is mixed with a small amount of black or its 
 
8 INTRODUCTION 
 
 complementary color, we get a gradation of that color 
 darker in appearance than the original and this is called 
 a shade of the color. 
 
 The term shade is frequently misused to convey the 
 idea of hue. In the following pages the word shade will 
 be used to convey the idea of a pigment darkened by 
 the addition of black or another pigment complemen- 
 tary to it. 
 
 Top Hue and Under Hue. When different thicknesses 
 of a medium are used, there is in some cases a different 
 amount of color absorption for the varying thicknesses 
 of the medium and this causes a variation in the color 
 or the hue of the medium. Thus a dilute or thin solu- 
 tion of magenta shows a pink of blue hue, while a so- 
 lution of very great depth or strength is a deep red. 
 Cobalt glass when very thin, shows a blue color, while as 
 the thickness increases, it becomes purple and finally if 
 a sufficiently great thickness be employed the color is a 
 deep red. 
 
 The cause of this action is that there is an unequal co- 
 efficient of absorption between the different densities. At 
 varying densities the absorption curve takes in or ex- 
 cludes different parts of the spectrum and the result is 
 that the apparent color is of different hues, depending on 
 the proportionate increase or decrease of the absorption. 
 
 When the medium is an opaque pigment and is spread 
 on paper in a solid band so as to completely shut out 
 the white of the paper or if the pigment is viewed in a 
 mass, it shows the absorption that a dense solution would 
 show; but when diluted with a white pigment or printed 
 thinly on paper we get the same condition of unequal 
 absorption as occurs in dilute or thin solutions, and a 
 
INTRODUCTION 9 
 
 hue of the original color is the result, the white pigment 
 or the white light of the paper acting as a dilutent. On 
 account of this we often get a red of yellow hue in the 
 mass while on rubbing or printing it out thinly or dilut- 
 ing with white we get a red of blue hue. From this 
 explanation it can be readily seen that we can have a 
 number of these variations between the material in mass 
 and the same material diluted, or printed out thinly. 
 The hue of the color when taken in the mass or undi- 
 luted we will call the top hue while the diluted or thinly 
 spread out hue we will call the under hue of a color. 
 
 Color Strength. By the term color strength of a pig- 
 ment is meant the actual amount of color it contains and 
 is measured by its tinting power when mixed with white. 
 This of course is a measure of the relative power a pig- 
 ment has to impart its hue or color to another pigment. 
 The color strength of a pigment varies inversely with its 
 crystalline character, the more amorphous a pigment is 
 the greater will be its color strength. 
 
 Abrasive Quality. If a pigment contains any hard 
 material it is apt to exert an abrasive action on plates, 
 forms and cuts and to wear down the fine lines so that 
 sharpness and definition will be lacking. This not only 
 destroys the effectiveness of the work but also shortens 
 the life of the plate or cut. 
 
 Fineness. This word is used in its ordinarily accepted 
 meaning. In this connection it is well to note that tak- 
 ing the term abrasive quality in the sense shown above, 
 a material can be quite fine and at the same time can be 
 abrasive. A great degree of fineness is necessary in all 
 pigments to be used in ink making not only on account 
 of the fine lines and delicate tone effects which would 
 
io INTRODUCTION 
 
 not be brought out unless the pigment was ground very 
 finely but also because a coarse pigment has a tendency 
 to collect into balls and to give a granular effect to the 
 ink. Precipitated colors frequently appear coarse but 
 when rubbed under the finger this apparent coarseness 
 disappears. 
 
 Oil Absorption. On account of differences in the phys- 
 ical structure of pigments the amount of oil necessary 
 to make a thin paste varies, some pigments taking more 
 than others; the measure of this quality is called the oil 
 absorption of a pigment. 
 
 Livering. When an ink, on standing, thickens to a 
 spongy, rubber-like mass it is said to liver. This is due 
 to a chemical action between the pigment and the vehi- 
 cle, such as the rapid oxidation of the oil, or the forma- 
 tion of a soap. When a pigment shows a tendency to 
 liver it cannot be regarded as a good ink-making pigment. 
 * Shortness. If a pigment when mixed with a large 
 quantity of oil still remains stiff or cannot be drawn out 
 into a string between the fingers but breaks, it is said to 
 be short. While there are some classes of work that re- 
 quire an ink of a certain degree of shortness, as a general 
 rule, pigments that show this property are not suited for 
 making inks. 
 
 Flow and Length. Flow is the property of a pigment 
 to combine with a good body the abilty to run and feed 
 well on the press. An ink that flows well must also have 
 the property of being drawn out into a string between 
 the fingers and this is called length. Thus each of these 
 terms suggests or includes the other; they are both some- 
 times spoken of under the name of viscosity. For all 
 classes of work these properties are very essential and a 
 
INTRODUCTION II 
 
 pigment that does not show them to some extent should 
 be avoided. 
 
 Tack and Softness. Tack is that property of cohesion 
 between particles of ink that can best be described as 
 the pulling power of the ink against another surface. 
 When there is very little cohesion and the property of 
 tack is almost absent we have what we shall designate 
 as softness. 
 
 Body Color. Body color is the color of the dry pig- 
 ment before it is mixed with a vehicle. The addition of 
 a vehicle frequently makes a decided difference in the 
 color of a pigment. 
 
 Transparency. Transparency will be used in the 
 general sense of the word, namely a pigment or ink that 
 allows color or light from another source to pass through 
 it. 
 
 Opacity. Opacity is the property of absolutely stop- 
 ping the transmission of light or color from another 
 source. A transparent color can be rendered more or 
 less opaque by the addition of a base, while many 
 opaque pigments can be made to some extent transparent 
 if they are laid on or printed in a thin film and some 
 few can be made to appear transparent to a slight degree 
 by the addition of other materials. The opacity or 
 covering power varies as does the color strength with 
 the crystalline character of the pigment. 
 
 Body. The body of a pigment is the measure of its 
 density. This term is variously used, generally to con- 
 vey the idea of a property not readily explainable. Thus 
 it is sometimes spoken of to convey the idea of covering 
 power, and this is due to the fact that the denser an ink 
 is the more covering power it will have. As regards its 
 
12 INTRODUCTION 
 
 use in this volume it is the measure of the consistency 
 and density of the ink. Thus a stiff ink that stands is 
 said to have a good body while an ink that is soft and 
 runny is said to lack body. 
 
 Incompatibility. Incompatibility means that for some 
 reason, physical or chemical, a pigment cannot be used 
 with another pigment or with certain vehicles or under 
 certain circumstances. The fact that we cannot use 
 lead colors with those containing sulphur is a well- 
 known example of this. Another illustration is the fact 
 that colors affected by alkalies should not be used to 
 print labels for soap or lye cans. 
 
 Bleeding. Certain pigments when mixed with water 
 or oil or any of the various printing-ink vehicles are 
 partially soluble and this solubility is called bleeding. 
 Pigments that bleed are not of much value for making 
 printing inks as they are apt to strike through the paper 
 or color the edge of the work. A pigment that is to be 
 used in dry work need not be entirely insoluble in water 
 but as a general rule a pigment that bleeds has not been 
 properly made. 
 
 Fastness to Light. This is used in the ordinary sense 
 of the word, that is, to mean the degree of resistance the 
 color has to the changing action of ordinary light. 
 
 Atmospheric Influences. Closely allied to fading and 
 sometimes attributed to it, are other changes both phys- 
 ical and chemical caused by the influence of the atmos- 
 phere. 
 
 These may be produced in various ways, by oxidation, 
 reduction, the solvent action of gases and by chemical 
 combinations between the pigment and acid radicals 
 present in the air or on account of changes in the phys- 
 
INTRODUCTION 13 
 
 ical form of the color, due to dryness, moisture or ex- 
 tremes of temperature. The action of sulphur gases on 
 lead pigments and the greenish hue that prussian blue 
 assumes from exposure to oxidizing influences are com- 
 mon examples. 
 
PART ONE 
 
 TESTING OF MATERIALS 
 
 GENERAL LABORATORY APPARATUS, CHEMICAL AND 
 PHYSICAL TESTS 
 
 SECTION ONE. LABORATORY APPARATUS 
 
 THE following methods of analysis and tests of ink- 
 making materials have been compiled from various sources 
 too numerous and varied for us to attempt to give any 
 credit. All of them have been practically tried by the 
 authors and found to be satisfactory. 
 
 As the results obtained in testing depend entirely on 
 the accuracy and uniformity with which the work is done 
 and as this accuracy and uniformity depend in a great 
 measure on the apparatus employed, a brief description 
 of the standard apparatus employed by the authors in 
 testing inks and ink-making materials will be given. 
 Some of this apparatus is in general use for testing pig- 
 ments, inks and paints, some has been adapted from other 
 sources and some is original with us. 
 
 Muller and Slab. - - The slab used for rubbing colors 
 should be of smooth polished marble, perfectly level, set 
 in a heavy framed table that must be perfectly rigid. 
 The muller should be made of some close-grained, hard 
 material such as lithographic stone or a smooth, fine- 
 grained marble. It should be conical in shape to give 
 
16 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 a good purchase to the hands and to allow of its being 
 shoved with the maximum of downward pressure. The 
 one in use in our laboratory is 8 inches high, 3 inches 
 in diameter at the bottom and weighs about 4 pounds. 
 The place gripped by the hands is slightly roughened to 
 give a good purchase and the bottom is highly polished. 
 The surface of the slab must be absolutely true and 
 smooth so that the pressure will be uniform and to avoid 
 having the particles of color gather where they will not 
 get sufficient rubbing. A cut of the slab and muller, 
 showing the color rubbed out, is shown in Figure i. 
 
 FIGURE i. MULLER AND SLAB, SHOWING METHOD 
 OF RUBBING OUT COLORS. 
 
 Electric Muffle Furnace. An electric muffle furnace 
 will be found invaluable, as with it almost any range of 
 temperature can be obtained and it is far superior to the 
 bunsen burner for ashing materials and burning precipi- 
 tates. It is easily regulated and will reproduce at any 
 
TESTING OF MATERIALS 
 
 time a definite condition of temperature used previously, 
 so that work can be duplicated at different times under 
 exactly similar conditions. 
 
 Electric Combustion Furnace. An electric combus- 
 tion furnace will also be found to be far more satisfactory 
 than the ordinary gas combustion furnace. 
 
 Constant Temperature Oven. - - The most satisfactory 
 constant temperature 
 oven is an electric one. 
 The one we use has an 
 easily controlled range 
 from 75 to 150 C. 
 
 There are also electri- 
 cal hot plates and heat- 
 ing apparatus of almost 
 every description which 
 are more satisfactory 
 than the gas burning 
 ones, and by the use of 
 these electrical devicea 
 in a laboratory the 
 danger of fire is almost 
 entirely eliminated. 
 
 Mixing Machine. - 
 For mixing small ex- 
 perimental batches of 
 ink we use an electrically driven mixer, the picture of 
 which is shown in Figure 2. This mixer takes an iron 
 mixing pan Q| inches in diameter and 4 inches deep, 
 which will hold about 2 pounds of material. The dry 
 color and oil are weighed directly into the tared pan and 
 it is then set on the mixer. 
 
 FIGURE 2. LABORATORY MIXER. 
 
i8 
 
 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 FIGURE 3. ULTRA-VIOLET LIGHT AND CASE FOR 
 TESTING THE EFFECT OF LIGHT ON COLORS. 
 
 Grinding Mill. 
 - For grinding 
 experimental 
 batches of ink 
 under the same 
 conditions as will 
 occur in ordinary 
 work (and this 
 is an important 
 factor, as all lab- 
 oratory work of 
 this sort should 
 be done as closely 
 as possible under 
 conditions that 
 can be dupli- 
 cated on a prac- 
 tical scale), we 
 have a small mill 
 made by the Kent 
 Machine Works 
 which is in every 
 way a duplicate 
 of their large 
 three-roll ink mill. 
 Ultra-Violet 
 Light For test- 
 ing the fastness 
 to light of various 
 pigments and 
 dyes we use an 
 ultra-violet light. 
 This light is 
 
TESTING OF MATERIALS 19 
 
 mounted in a sheet-iron hood 3 feet by 3 feet at the 
 base, sloping up in the form of a pyramid enclosing the 
 lamp as shown in Figure 3. The bottom of the light 
 is set 21 inches above the bottom of the hood, which is 
 fitted with a hinged door and drawer for convenience 
 in placing the samples. As the rays given off by this 
 light are very injurious to the eyes, a look-in-hole is 
 provided, high enough up so that the light itself 
 can be seen, and is covered with a Hallauer No. 64 glass 
 for cutting off the ultra-violet rays. This light develops 
 about the same intensity as strong sunlight but has the 
 advantage of being always uniform and can be used in 
 any sort of weather. 
 
 Balances. An accurate analytical balance is, of course 
 a necessity. For rougher yet somewhat accurate work 
 where small amounts are to be weighed a small "prescrip- 
 tion" balance will be found useful as will also a balance 
 of the "Robervahl" type with a capacity of from 5 to 10 
 pounds. For ordinary heavy work a small platform scale 
 that will weigh down to ounces and up to 100 pounds is 
 necessary. 
 
 Microscope. A good microscope with a photographic 
 attachment is also a great adjunct in work on pigments, 
 especially in determining their physical characteristics 
 and the bases on which aniline lakes are precipitated. 
 This branch of work is only beginning to be recognized 
 and given its proper place in the color testing laboratory. 
 
 Filtering Apparatus. For filtering large experimental 
 batches of color a small filter press may be used but this 
 will not be found any more satisfactory than the more 
 simple rectangular frame with pins from which a filter 
 cloth is suspended. 
 
20 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 Oil Tanks and Cups. Several small copper tanks 
 with covers and wide opening spigots should be used to 
 hold oils and varnishes for use in the laboratory and we 
 have found a few cups with tops that lift back and a lip 
 fashioned after the ordinary molasses pitcher are very use- 
 ful when weighing out oils, varnishes and other liquids. 
 
 Glass Plates. For testing and comparing color 
 strength and top hue a thin colorless glass plate similar 
 to those used to make photographic slides should be 
 provided. 
 
 Thermometers. The laboratory should be provided 
 with sufficient thermometers of various ranges and an 
 accurate pyrometer will be found of great use in deter- 
 mining high temperatures. 
 
 Hydrometers. A set of 6 hydrometers divided as 
 follows will be found to give a very useful range; Specific 
 Gravity, .700 to .800, .800 to .900, .900 to i.ooo, i.ooo 
 to 1.200, 1.200 to 1.400 and 1.400 to 1.600. These in- 
 struments should be graduated to read .5 of a degree in 
 the fourth place. A set giving Beaume readings for 
 getting correct strength solutions for precipitations and 
 the like is also necessary. 
 
 Viscosimeters. The viscosimeter employed by us for 
 the determination of viscosity in raw oils is the regular 
 type of Engler viscosimeter, standardized against water. 
 Figure 4 shows the one used for testing boiled or burnt 
 oils and varnishes. It is a copper cylinder with a steam 
 jacket so that the oil and jacket can be kept at a constant 
 temperature of 100 C. Its inside dimensions are 12 
 inches by 4^ inches, and it has marks so that the same 
 amount of oil or varnish can be used each time. The 
 amount of oil used in the one in use in our laboratory is 
 
TESTING OF MATERIALS 
 
 21 
 
 1200 c.c., and of this 
 amount 1000 c.c. are run 
 out in the test. The bottom 
 of the cylinder is pitched 
 slightly to make the flow 
 even and the orifice out 
 of which the oil flows is a 
 stop cock with a J inch 
 opening fitted with a long 
 handle so that it operates 
 easily and quickly. The 
 jacket is fitted with a ther- 
 mometer as is also the top 
 of the cylinder. The ther- 
 mometer in the top ex- 
 tends well into the oil about 
 in the center of the viscosi- 
 meter; the one in the 
 jacket shows the temper- 
 ature of the jacket. The 
 apparatus should be leveled 
 when set and should be 
 fastened securely. 
 
 We find this piece of 
 apparatus invaluable in de- 
 termining the consistency 
 of oils and varnishes of 
 heavy viscosity. The re- 
 sults are only relative, 
 however, as the instrument 
 is standardized against oils 
 
 and varnishes known to FIGURE 4. VISCOSIMETER FOR TESTING 
 , . f HEAVY BODIED OILS AND VARNISHES. 
 
 be satisfactory. 
 
22 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 Steam Jacketed Kettle. A steam jacketed kettle cf 
 the regular type holding about five or ten gallons will 
 be found indispensable. 
 
 Crocks and Miscellaneous. Several stoneware crocks 
 from five to twenty gallons capacity should be provided 
 for precipitating colors. 
 
 A motor-driven stirring machine, a number of heavy 
 glass rods, smooth metal bars and wooden paddles, and 
 several low wooden trestles should also find a place in 
 the laboratory equipment. 
 
 SECTION TWO. METHODS OF ANALYSIS 
 
 LINSEED OIL 
 
 Specific Gravity. Specific gravity may be determined 
 with a pyknometer or hydrometer at 15.5 C. For most 
 control work an accurate hydrometer, reading to one-half 
 a degree in the fourth place will be found as satisfactory 
 as a pyknometer, providing the oil is uniformly cooled, 
 the hydrometer immersed without touching the sides of 
 the jar and the reading carefully taken. There should 
 be no air bubbles in the liquid at the time of reading. 
 
 The specific gravity of a raw oil should be above .931, 
 but, inasmuch as ageing, blowing and other permissible 
 treatments that do not bring the oil into the class of a 
 boiled oil, increase the gravity, it is useless to give a high 
 limit for specific gravity. Boiled or burnt oils, or oils 
 that have had driers added to them show a still higher 
 gravity. 
 
 Viscosity. The viscosity should be taken on an 
 Engler viscosimeter at 20 C., water being taken as the 
 standard. It is essential in order to get concordant 
 
TESTING OF MATERIALS 23 
 
 results that both the water in the jacket and the oil 
 remain at the proper temperature throughout the whole 
 operation. 
 
 Flash. The flash should be taken in a Cleveland 
 open fire tester or some similar instrument in the follow- 
 ing manner: The cup is put in the center of a ring of 
 asbestos, extending all around it about 2 inches, and set 
 on a tripod over a bunsen burner with the flame so 
 regulated that the temperature of the oil will rise about 
 9 C. per minute. As a test flame, use an ordinary blow 
 pipe attached to a rubber tube. Begin testing when the 
 temperature of the oil reaches 250 C. and test for every 
 rise of three degrees. When applying the test flame move 
 it slowly across the oil in front of the thermometer a 
 little above the surface of the oil. The flash is the low- 
 est temperature at which the vapors above the oil 
 flash and go out. Care should be taken that the oil is 
 not foaming when the flame is applied, as the bubbles 
 will burst and give an incipient flash which will, of course, 
 be low. 
 
 Fire Point. After determining the flash point, con- 
 tinue heating the oil until the vapors when ignited con- 
 tinue to burn. The temperature at which this occurs is 
 called the fire point. 
 
 Drying on Lead Monoxide. This test is similar to 
 Livache's drying test, only litharge is used instead of 
 precipitated lead. Weigh out about 5 grams of lith- 
 arge into a tared watch glass, spreading the litharge on 
 the bottom of the glass; distribute as evenly as pos- 
 sible over the litharge from .2 to .5 grams of oil. Take 
 the exact weight of the oil and the exact weight of the 
 watch glass, oil, and litharge, expose to the air and 
 
24 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 light for from 76 to 96 hours, weigh again and the gain 
 is calculated in percentage from the original weight of 
 the oil used. A chemically pure litharge must be used 
 in this determination to get uniform results. 
 
 Acid Value. Ten grams of oil are weighed into a 
 200 c.c. Erlenmeyer flask and 50 c.c. of neutral alcohol 
 added, heat on a steam bath for one-half hour, cool and 
 titrate with one-tenth normal sodium hydrate, using 
 phenolphthalein as an indicator; calculate the acid 
 value as milligrams of potassium hydrate per gram of 
 oil. The acid value varies as does the gravity with age 
 and blowing or treatment but should be less than 8. 
 
 Saponification. Weigh 2 to 3 grams of oil into a 
 200 c.c. Erlenmeyer flask: add 30 c.c. one-half normal 
 alcoholic potash, connect with a reflux condenser, heat 
 on a steam bath for i hour; titrate with one-half normal 
 sulphuric acid using phenolphthalein as an indicator. 
 Always run two blanks with the alcoholic potash. From 
 the difference between the cubic centimeters of acid 
 required by the blanks and the sample calculate the 
 saponification number in terms of milligrams of potas- 
 sium hydrate to one gram of oil. The saponification 
 number of linseed oil should be about 190. 
 
 Unsaponifiable Matter. Saponify 5 grams of oil with 
 about 200 c.c. one-half normal alcoholic potash for an 
 hour on a steam bath, using a reflux condenser and evap- 
 orate the alcohol; take up in water and transfer to a 
 separatory funnel, cool, shake out with two portions of 
 50 c.c. each of petroleum ether; wash the petroleum 
 ether twice with water, evaporate the petroleum ether 
 and weigh the unsaponifiable matter, which in raw lin- 
 seed oil should not be over 1.5 per cent. 
 
TESTING OF MATERIALS 25 
 
 Iodine Number. Weigh out from .2 to .25 gram of oil, 
 transfer to a 350 c.c. bottle with a well ground glass 
 stopper: dissolve the oil in 10 c.c. of chloroform and 
 add 30 c.c. of Hanus solution: let it stand with occa- 
 sional shaking for one hour: add 20 c.c. of a 10 per cent 
 solution of potassium iodide and 150 c.c. of water and 
 titrate with standard sodium thiosulphate, using starch 
 as an indicator. Blanks must be run each time and from 
 the difference between the amounts of sodium thiosul- 
 phate required by the blank and the sample calculate 
 the iodine number (centigrams of iodine absorbed by 
 one gram of oil). 
 
 The Hanus solution is made by dissolving 13.2 grams 
 of iodine in 1000 c.c. of glacial acetic acid and adding 
 3 c.c. of bromine. 
 
 Foots and Turbidity. Let one liter of oil stand in 
 a clear glass bottle for eight days and note the amount 
 of sediment formed. In very cold weather the oil will 
 sometimes show a turbidity due to the freezing out of 
 fats of very high melting point. It is therefore well in 
 cold weather to heat a portion of the oil to about 100 C. 
 and allow it to cool. If the turbidity does not return 
 the oil should not be reported as turbid. 
 
 Ash. Burn about 20 grams in a porcelain dish and 
 weigh the ash. A pure raw linseed oil should contain 
 only a trace of ash. In a boiled oil the ash will 
 show the metallic driers. Make a qualitative test for 
 these. 
 
 Break. Heat 50 c.c. of oil in a small beaker up to 
 300 C. rapidly. If a jelly-like mass separates out, 
 the oil has broken. This determination is influenced by 
 the rate of heating to such an extent that it is difficult, 
 
26 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 unless the heating is done very rapidly, to get the same 
 oil to act twice in the same way. 
 
 Drying with Manganese Borate. One gram of oil 
 and .2 gram of manganese borate are spread on a glass 
 plate very thin and the time of drying noted. 
 
 Rosin. (Liebermann-Storch Test.) To 20 grams of 
 oil, add 50 c.c. of alcohol, heat on the steam bath for 
 about fifteen minutes, cool, decant the alcohol, evaporate 
 to dryness, add 5 c.c. of acetic anhydride, warm, cool 
 and add a drop of sulphuric acid, 1.53 specific gravity. 
 Rosin or rosin oil will give a fugitive violet color. The 
 conclusiveness of this test is open to doubt. 
 
 DETERMINATION OF CALCIUM CARBONATE IN 
 PARIS WHITE 
 
 Weigh .5 gram of the sample into an Erlenmeyer flask, 
 add 60 c.c. of fifth normal hydrochloric acid, close the 
 flask with a reflux condenser about 2 feet long. Boil 
 until steam comes from the tube; remove the flask and 
 wash the tube into it, add a few drops of phenolphthalein 
 and run in one-fifth normal alkali until the color just turns 
 red. Calculate the calcium carbonate from the number 
 of c.c. of alkali required. Lime may also be determined 
 gravimetrically by precipitation in the following manner: 
 .5 gram of the sample is dissolved in hydrochloric acid, 
 the insoluble matter is filtered off, the filtrate is made 
 alkaline with ammonia in slight excess and boiled. If 
 iron and aluminum precipitate, the solution is filtered 
 and washed with hot water, the filtrate to which more 
 ammonia has been added is then boiled and a boiling 
 solution of ammonium oxalate is added and the solution 
 allowed to boil for about fifteen minutes, allowed to 
 
TESTING OF MATERIALS 27 
 
 stand until settled and filtered; wash with hot water; 
 burn off filter paper, blast for fifteen minutes and weigh 
 as calcium oxide. By burning and weighing the insol- 
 uble residue the amount can be determined as can also 
 the iron and aluminum oxides by burning and weighing 
 the precipitate from the addition of ammonia. If it is 
 desired to separate the iron from the aluminum this can 
 be done by dissolving the mixed oxides in sulphuric acid, 
 reducing with zinc and titrating with permanganate. 
 
 Magnesia may be determined in the filtrate from the 
 lime as follows: evaporate in an acid solution to about 
 250 c.c. add about 25 c.c. of a solution of microcosmic 
 salts, cool, add ammonia drop by drop with constant stir- 
 ring until slightly ammoniacal; add about one-half the vol- 
 ume of ammonia and let stand over night; filter and wash 
 with water containing ammonia and ammonium nitrate. 
 Ignite and weigh as magnesium pyro-phosphate. 
 
 BARYTES 
 
 A microscopic examination of barytes should be made 
 to determine the evenness of grinding, the size and 
 angularity of the particles and whether it is amorphous 
 or crystalline. 
 
 The only determination generally necessary for barytes 
 is the amount of insoluble in hydrochloric acid. This 
 insoluble can generally be considered barium sulphate 
 but to make sure that there is no silica present, it is al- 
 ways well to evaporate with sulphuric and hydrofluoric 
 acids. 
 
 Natural barytes is sometimes contaminated with cal- 
 cium fluoride. Test qualitativly for fluorides by moisten- 
 ing with water in a platinum dish, adding sulphuric acid 
 
28 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 and gently heating. The top of the dish should be 
 covered with a glass coated with paraffine with several 
 marks scratched through to the glass. If fluorides are 
 present the glass not covered by the paraffine will be 
 etched. If there is any amount of soluble salts, iron, 
 aluminum, lime, etc., they can be determined in the nitrate 
 from the insoluble in the way outlined under paris white. 
 If lime is present determine the soluble sulphate in i gram 
 dissolved in hydrochloric acid and filtered. To the 
 boiling filtrate add barium chloride, let stand, filter, 
 ignite and weigh; calculate to calcium sulphate. If 
 there is any lime left over and carbonates are present, 
 calculate the remainder to calcium carbonate, unless 
 the presence of fluorides is detected. 
 
 LITHOPONE 
 
 Barium Sulphate and Insoluble. Dissolve i gram in 
 hydrochloric acid, adding a small amount of potassium 
 chlorate, evaporate to about one-half, dilute with water, 
 add 5 c.c. dilute sulphuric acid, boil, allow to settle, 
 filter, ignite and weigh. This is the barium sulphate 
 and insoluble. 
 
 Total Zinc Oxide. Heat the filtrate to boiling, add 
 sodium carbonate drop by drop until all the zinc is pre- 
 cipitated as carbonate, filter on a Gooch crucible, warm, 
 ignite and weigh as zinc oxide. 
 
 Zinc Sulphide. Digest i gram in 100 c.c. of i per 
 cent acetic acid at room temperature for one-half hour, 
 filter and wash, determine zinc in filtrate by sodium 
 carbonate. The difference between the total zinc oxide 
 and the zinc oxide soluble in acetic acid, multiplied by 
 1.1973 gives the zinc present as sulphide. 
 
TESTING OF MATERIALS 29 
 
 Barium Carbonate. Digest 2 grams with boiling 
 dilute hydrochloric acid, dilute with hot water, filter, 
 and determine barium in the filtrate by precipitation 
 with sulphuric acid. Figure as barium carbonate. 
 
 WHITE LEAD 
 
 Insoluble and Total Lead. Weigh one gram of the 
 sample, moisten with water, dissolve in acetic acid, filter, 
 wash, ignite and weigh the insoluble. To filtrate from 
 insoluble matter, add 25 c.c. sulphuric acid (i: i), evap- 
 orate and heat until acetic acid is driven off; cool, dilute 
 to 200 c.c. with water, let stand for two hours, filter on 
 a Gooch crucible, wash with i per cent sulphuric acid, 
 ignite at low heat and weigh as lead sulphate. 
 
 Carbon Dioxide and Water. In determining carbon 
 dioxide heat i gram in a combustion furnace, catching 
 the water in a calcium chloride tube and the carbon 
 dioxide in a potash bulb; by weighing the residue left 
 in the boat the exact composition can be calculated. 
 
 Calculate the carbon dioxide to lead carbonate, sub- 
 tract the lead oxide necessary to form the carbonate 
 from the total lead oxide present and calculate the re- 
 maining lead oxide to lead hydroxide. Calculate the 
 water necessary for the lead hydroxide and subtract 
 it from the total water and the remaining water can be 
 reported as moisture. 
 
 In determining carbon dioxide the method in most 
 common use now is to pass the evolved gas through a 
 solution of barium hydroxide, filter as rapidly as possi- 
 ble with the greatest exclusion of air liable to contain 
 carbon dioxide, wash in boiling water, dissolve in hydro- 
 chloric acid and determine as barium sulphate. Cal- 
 
30 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 culate the amount of carbon dioxide from the barium 
 sulphate. 
 
 CALCIUM SULPHATE 
 
 Determine sulphate by precipitation with barium chlo- 
 ride as described under barytes. 
 
 In another portion determine insoluble and in the 
 nitrate from the insoluble determine lime by precipita- 
 tion with ammonium oxalate. 
 
 ZINC OXIDE 
 
 Determine zinc, after solution, as carbonate, as de- 
 scribed under lithopone. 
 
 CHROMIUM COLORS 
 Chrome Yellow, Chrome Orange, Chrome Red 
 
 A microscopic examination will show the character 
 of the pigment, whether it is crystalline or amorphous. 
 
 Dissolve .5 gram in hydrochloric acid, filter off insolu- 
 ble, dilute the filtrate to 400 c.c., almost neutralize with 
 ammonia, pass in a rapid stream of hydrogen sulphide 
 until all the lead is precipitated as lead sulphide, filter, 
 wash with water containing some hydrogen sulphide, 
 dissolve the lead in dilute nitric acid, add an excess of 
 sulphuric acid, heat to fuming and determine the lead 
 as sulphate in the usual way. 
 
 Chromium. Evaporate the filtrate from the lead 
 sulphide to small bulk, add ammonia to excess, boil until 
 the pink color disappears, filter, wash with hot water, 
 ignite and weigh as chromium oxide. 
 
 Sulphate. Weigh one gram, dissolve in hydrochloric 
 acid, dilute considerably and determine the sulphate by 
 precipitation with barium in the usual way. 
 
TESTING OF MATERIALS 31 
 
 Chrome Green 
 
 A microscopic examination will show the character 
 of the particles and also if it is a dry mixture or made 
 by simultaneous precipitation. A badly made green 
 will show yellow and blue as well as green, while a well 
 made green will show green and some blue but no yellow. 
 
 The analysis of the green is carried on in the same 
 way as for chrome yellow except that the sample is 
 first gently ignited in a porcelain crucible to decom- 
 pose the blue. 
 
 The precipitate with ammonium hydroxide also con- 
 tains iron besides the chromium, and it is necessary to 
 dissolve this precipitate with hydrochloric acid on the 
 filter and make it up to a definite volume. One part 
 of this is taken and sodium peroxide added in suffi- 
 cient amount to render the solution alkaline and to 
 oxidize to chromate, boil until all of the hydrogen per- 
 oxide is driven off, cool, make acid with sulphuric acid, 
 add a measured excess of standard ferrous sulphate and 
 titrate the excess of iron with standard potassium 
 bichromate. 
 
 Determine iron in another portion by reduction and 
 titration with potassium permanganate. 
 
 VERMILLION 
 
 About the most satisfactory way to determine the 
 purity of vermillion is to ash one gram of the pigment. 
 Not more than .5 per cent should remain. 
 
 Vermillion should also be tested for dye toners by being 
 shaken with alcohol, chloroform and hot water and filtered. 
 If the filtrate shows color it is an indication of dye. 
 
32 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 IRON OXIDE AND EARTH PIGMENTS 
 
 It is seldom necessary to analyze these pigments but 
 when it is the iron and insoluble can be determined in 
 the usual way. 
 
 Manganese. For those pigments that contain man- 
 ganese, dissolve .2 gram in nitric acid with heat and add 
 75 c.c. of strong nitric acid, boil and add 5 grams po- 
 tassium chlorate, heat to boiling, add 50 c.c. more strong 
 nitric acid and a little more potassium chlorate, boil 
 until fumes cease to come off, cool, filter on asbestos 
 and wash with strong nitric acid, suck dry and wash 
 out the remaining nitric acid with water, transfer pre- 
 cipitate and asbestos to a beaker, add a measured excess 
 of standard ferrous sulphate in dilute sulphuric acid, stir 
 until all the manganese dioxide is dissolved and titrate the 
 remaining ferrous sulphate with potassium permanganate. 
 A ferrous solution of the proper strength is made by 
 dissolving 10 grams of crystallized ferrous sulphate in 
 900 c.c. of water and 100 c.c. of sulphuric acid. 
 
 FERROCYANIDE BLUES 
 Prussian Blue, Bronze Blue, Chinese Blue 
 
 Insoluble. Ignite one gram in a porcelain crucible 
 at a low temperature, add 25 c.c. strong hydrochloric 
 acid, boil until all the iron is decomposed, add water, 
 bring to a boil again and filter, wash with hot water, 
 ignite and weigh the insoluble. 
 
 Iron. Make up filtrate to volume and in an aliquot 
 part determine iron by reduction with zinc and titration 
 with potassium permanganate. 
 
 Aluminum. In another portion the iron and alumi- 
 
TESTING OF MATERIALS 33 
 
 num oxides may be precipitated with ammonia and the 
 aluminum found by difference from the total oxides 
 and the amount of iron found by titration. 
 
 Dyes. It is well also to test the blues for dye toners 
 by shaking them up in the various solvents. This 
 should be very carefully done as it is sometimes very 
 difficult to filter out the blue due to the formation of a 
 colloidal solution. This is frequently taken to be a dye 
 but in reality is the blue itself. 
 
 ULTRAMARINE BLUE 
 
 An analysis of ultramarine blue is of very little value. 
 The principal determinations are, however, aluminum, 
 silica, soda, total sulphur, sulphur as sulphate and sul- 
 phur as sulphide. 
 
 Silica. Silica is determined by solution, evaporation 
 to dryness, resolution and filtration, the residue being 
 ignited and weighed. 
 
 Aluminum. Aluminum is determined in the filtrate from 
 the silica by precipitation with ammonium hydroxide. 
 
 Soda. Soda is determined in the filtrate from the 
 aluminum by adding sulphuric acid, evaporating to dry- 
 ness and weighing as sodium sulphate. 
 
 Total Sulphur. Mix i gram of pigment with 4 grams 
 of sodium carbonate and 4 grams of sodium peroxide in 
 a nickel crucible, cover with about a gram of sodium 
 carbonate, fuse, using an asbestos shield to prevent the 
 sulphur from being taken up from the gas; dissolve the 
 fused mass in water, make acid with hydrochloric acid, 
 precipitate with barium chloride and weigh as barium 
 sulphate. 
 
 Sulphur as Sulphate. Dissolve one gram in hydro- 
 
34 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 chloric acid, boil till hydrogen sulphide is driven off, 
 add barium chloride and weigh as barium sulphate. 
 Subtract sulphur as sulphate from total sulphur and 
 remainder is sulphur as sulphide. 
 
 ORANGE MINERAL 
 
 Dissolve .25 gram of sample in 50 c.c. of a solution 
 containing 1000 c.c. water, 126 c.c. nitric acid and 600 c.c. 
 one-fifth normal oxalic acid. Then add 25 c.c. of 25 per 
 cent sulphuric acid and titrate with permanganate; run 
 a blank and calculate the difference to lead dioxide. 
 
 BLACKS 
 
 Total Ash. Weigh one gram into a platinum dish and 
 burn off carbon at a very low temperature. 
 
 Insoluble Ash. Transfer total ash to beaker, moisten 
 with water, add 25 c.c. strong hydrochloric acid, boil for 
 fifteen minutes, dilute with water, bring to boil again, 
 filter off insoluble, wash with hot water and weigh after 
 ignition. 
 
 ANALYSIS or SOLUBLE ASH 
 
 Phosphates. Make up filtrate from insoluble matter 
 to 500 c.c., if phosphates are present, draw off an aliquot 
 portion, make alkaline with ammonia and acid with nitric 
 acid, heat the solution on a water bath to 60 C. add 
 50 c.c. molybdate solution, heating at this temperature 
 for one hour, filter and wash with a wash solution contain- 
 ing nitric acid, ammonium nitrate and a small amount of 
 molybdate solution about three times. Dissolve the 
 precipitate on the filter with ammonia, allowing the solu- 
 tion to run into the original beaker. Precipitate with 
 
TESTING OF MATERIALS 35 
 
 hydrochloric acid and add ammonia in slight excess to 
 redissolve the precipitate, cool, add 10 c.c. magnesia 
 mixture and about one-half the volume of ammonia, stir, 
 allow to stand over night, filter, wash with solution con- 
 taining one part ammonia and three parts water, ignite, 
 weigh and calculate to phosphoric anhydride. 
 
 Lime. To another portion of the original solution 
 add ammonia to alkalinity and make acid with acetic 
 acid, filter, wash with hot water, boil the filtrate and add 
 boiling ammonium oxalate, boil for a few minutes longer, 
 allow to settle, filter, wash with hot water and weigh, 
 after blasting, as calcium oxide. 
 
 Sulphates. Determine sulphates in another portion 
 with barium chloride. 
 
 Iron. Take another portion of the original solution 
 and add 15 c.c. of dilute sulphuric acid, evaporate to 
 expel hydrochloric acid, take up with water, reduce with 
 zinc and titrate with permanganate. When the black 
 does not contain phosphates determine lime, iron and 
 sulphates in the usual way. 
 
 Blacks are occasionally toned with prussian blue, and 
 to determine this boil the sample with a 4 per cent solu- 
 tion of sodium hydroxide, filter, make acid with hydro- 
 chloric acid and add a solution containing a mixture of 
 ferrous and ferric chloride or sulphate. A blue precipitate 
 indicates the presence of prussian blue. 
 
 ORGANIC LAKES 
 
 The only available schemes for identifying the aniline 
 dyes used in lake pigments are much too complicated to 
 be gone into in this volume. However the book entitled 
 "Tests for Coal Tar Colors in Aniline Lakes" by George 
 
36 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 Zerr and Dr. C. Mayer will be found to be a great aid 
 in the examination of lake pigments. 
 
 SECTION THREE. PHYSICAL TESTS OF 
 PIGMENTS 
 
 Color Strength. .2 gram of the standard pigment 
 and one gram of zinc white are weighed out accurately 
 on an analytical balance and a like quantity of the pig- 
 ment to be tested and zinc white is also weighed. Trans- 
 fer these materials to a marble slab and add drop by drop 
 sufficient oil to the standard to make it into a stiff paste. 
 Add the same number of drops to the sample to be tested, 
 mix both piles separately and thoroughly with a palette 
 knife and rub each one 50 times with the muller de- 
 scribed under laboratory apparatus. Each rub-out is 
 then gathered up with a palette knife and rubbed again 
 25 times. After this final rubbing each sample is gathered 
 together on the slab and a small amount of each is put side 
 by side on a glass. If the sample shows weaker than the 
 standard it is weighed out again with the same amount of 
 zinc white and a little more color and the rubbing is re- 
 peated. This is done until the sample, with the color added, 
 exactly matches the standard. Thus, if for .2 gram of 
 the standard it takes .25 grams of the sample to make a 
 match, the sample is called 5 per cent weak; if, on the 
 other hand, the sample being tested shows stronger than 
 the standard, zinc white is added to reduce the color to 
 a match and the sample is said to be strong. 
 
 The authors have failed to get satisfactory results by 
 using a greater amount of white as the difference in the 
 strength is not so apparent under these circumstances 
 as when a greater amount of color is used as recommended 
 
TESTING OF MATERIALS 37 
 
 above. The use of chrome green or prussian blue with 
 yellows has also been found not to give as satisfactory 
 and uniform results as the use of white. 
 
 Where colors differ greatly in hue, judgment must be 
 used in estimating their weakness or strength as it is 
 impossible to get two pigments of the same color that 
 differ in hue to look alike, and often this variation in hue 
 is taken for weakness in color strength. 
 
 Fineness. Fineness can be tested by the use of sieves 
 of very fine mesh or bolting cloth, but as printing inks 
 require colors of a great degree of fineness it is more 
 satisfactory to judge the fineness by rubbing the pigment 
 under the finger on a smooth piece of paper. After a 
 little experience the fineness of a pigment can be easily 
 judged by this method. 
 
 In some cases the microscope is of value in determining 
 fineness. 
 
 Top Hue and Under Hue. Weigh out one gram each 
 of the sample and standard and add the same amount 
 of oil to each, mix with a palette knife and rub each 
 50 times with a muller. Compare the top hues on 
 glass. Then take some of the material and rub it out 
 on a piece of paper side by side with the standard. 
 Where the color is rubbed out thin the under hue will 
 show up. 
 
 Bleeding in Oil. Allow the paper with the rub-outs 
 for under hue to hang for a day and if the oil that sepa- 
 rates out is colored, the pigment is soluble in the oil and 
 will bleed. This bleeding should be compared with the 
 standard. 
 
 A pigment that bleeds in oil to any great extent should 
 not be used in printing inks as it will strike through the 
 
38 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 paper and stain the other side, penetrate through a 
 color laid over it or spread from the lines and give the 
 work a dirty look. 
 
 Bleeding in Water. Weigh one gram of the sample 
 into an Erlenmeyer flask, shake up with 100 c.c. of dis- 
 tilled water, filter through a filter paper into a test tube 
 and if the filtrate is colored the material bleeds in water. 
 
 The degree of this bleeding should not be very great 
 as it shows either that the coloring matter in the lake is 
 soluble or that it is imperfectly fixed on the base, and 
 this condition is apt to cause trouble in classes of work 
 where the paper is used wet or is liable to come in 
 contact with water. 
 
PART TWO 
 
 MANUFACTURE AND PROPERTIES OF INK-MAKING 
 MATERIALS 
 
 SECTION ONE. DRY COLORS 
 1. REDS 
 
 VERMILLION 
 
 VERMILLION is the red sulphide of mercury HgS. There 
 are two forms of HgS, the black sulphide, which is amor- 
 phous and the red sulphide which is crystalline. Ver- 
 million, under the name of "Cinnabar" occurs in a great 
 many places but natural vermillion, at present, is not 
 found on the market as a pigment, as the artificial ver- 
 million is its superior in color and brightness. 
 
 The manufactured vermillion on the market today is 
 mostly made by the following process: 
 
 When metallic mercury is mixed with a concentrated 
 solution of potassium pentasulphide at a moderate tem- 
 perature a dark red powder is obtained, which is con- 
 verted by a concentrated solution of caustic potash into 
 bright red vermillion. As the color approaches bright 
 redness great care must be taken as too high a tempera- 
 ture will produce a dull red of brown hue. The material 
 is then washed with dilute caustic potash and after- 
 wards with water, until the alkaline reaction disappears. 
 
40 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 PROPERTIES or VERMILLION 
 
 Top Hue 
 
 Under Hue 
 
 Fineness 
 
 Bright red. 
 
 Red of orange hue. 
 
 Not very fine. 
 Lightens on grinding. 
 
 Flow 
 
 Incompatibility 
 
 Abrasive Qualities 
 
 Being heavy bodied it 
 does not make an ink that 
 flows well. 
 
 Cannot be used with pig- 
 ments containing lead. 
 
 Not abrasive. 
 
 Oil Absorption 
 
 Bleeding 
 
 Fastness to Light 
 
 Requires only a small 
 quantity of oil. 
 
 Does not bleed. When 
 toned with dye toners will 
 bleed in alcohol and other 
 solvents. 
 
 Fast to light unless 
 toned with dye toners. 
 
 Shortness 
 
 Drying 
 
 Smoothness 
 
 Somewhat short. 
 
 Poor drying pigment. 
 Will rub off even after a 
 long time. 
 
 Does not make a smooth 
 ink particularly for typo- 
 graphic work. 
 
 Behavior towards 
 Vehicles 
 
 Atmospheric Influences 
 
 Works up well but sepa- 
 rates on standing. 
 It also has a tendency to 
 stand up from the vehicle 
 when printed, the latter go- 
 ing into the paper. 
 
 Will turn brown after exposure to air. The most 
 widely held theory is that it gradually reverts to the 
 amorphous condition, that is to the black sulphide, 
 although this theory is by no means proven. This 
 seems however to be substantiated by the fact that 
 the red brown-hued pigment is produced when too 
 much heat is used. The same hue is produced when 
 an ink containing vermillion is subjected to prolonged 
 grinding. 
 The chemical composition of the two forms is the 
 same. 
 
PROPERTIES OF INK-MAKING MATERIALS 
 
 PROPERTIES OF VERMILLION Continued 
 
 Value as an ink-making 
 pigment 
 
 Vermillion is not a very good pigment to use in 
 printing inks. It is high priced and does not work 
 well as a typographic ink for the following reasons: 
 it prints out unevenly on account of its shortness 
 and being a poor drier it is liable to rub off and 
 offset. Being a heavy pigment it separates out of 
 the vehicle requiring remixing after standing a little 
 while. For plate printing it works fairly well but is 
 not of much value on account of its rubbing off, due 
 to lack of drying, separation on standing and its ten- 
 dency to darken. 
 
 There are many lake colors that can be used in 
 all cases requiring vermillion of lower cost, and that 
 will give better working results for all classes of 
 work. 
 
 2. BLUES 
 
 FERROCYANIDE BLUES 
 
 This type of blue comprises those pigments known as 
 Prussian blue, Chinese blue and bronze blue. They are 
 all of practically the same chemical composition, namely 
 ferric-ferrocyanide [Fe 4 (FeCN 6 ) 3 ]. This formula is how- 
 ever only theoretical as the commercial pigment varies 
 according to the method of manufacture and it is ex- 
 tremely doubtful if it is ever of the above composition 
 exactly. 
 
 Broadly the manufacture of these blues depends on 
 the mixture of a ferrous salt, usually ferrous sulphate 
 (copperas), with potassium ferrocyanide (yellow prussiate 
 of potash) and the oxidation of the ferrous iron to ferric 
 iron by a powerful oxidizing agent. These three varieties 
 of ferrocyanide blues, while they have the same approx- 
 imate chemical composition, differ from each other 
 
42 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 slightly in this and to somewhat a greater extent in 
 physical characteristics. This variation is due to differ- 
 ences in the formula brought about by differences in the 
 manufacture. These modifications will therefore be taken 
 up in order. 
 
 A. Prussian Blue. This is the darkest variety of 
 ferrocyanide blue and has a decided red hue. For mak- 
 ing a soft-drying prussian blue of good red hue the fol- 
 lowing process will be found satisfactory. 
 
 Solution No. 1 468 Ibs. Potassium Ferrocyanide 
 
 2 344 " Ferrous Sulphate 
 
 (dissolved in the same amount of water) 
 
 3 110 Ibs. 66 Be Sulphuric Acid 
 
 4 850 " 35 Be Commercial Nitrate of Iron 
 
 5 44 " Sulphate of Aluminum in water 
 
 6 112 " Sodium Carbonate in water 
 
 Heat solutions No. i and No. 2 to boiling and run simul- 
 taneously into a tub of boiling water with constant stir- 
 ring. When precipitation is complete add solutions No. 3 
 and No. 4, boil until oxidation is complete, wash free from 
 iron and add No. 5 followed by No. 6; filter without 
 washing and dry at 160 F. The filtrate contains about 
 25 pounds of blue as sodium ferrocyanide, which can be 
 obtained by acidifying, precipitating with ferrous sul- 
 phate and oxidizing with commercial nitrate of iron. 
 This gives a good pigment at moderate cost. 
 
 B. Chinese Blue. This is a light variety of ferro- 
 cyanide blue with somewhat of a green hue. Its method 
 of manufacture is similar to prussian blue as described 
 before, only it is oxidized with hydrochloric acid and 
 potassium chlorate without the final addition of alkali. 
 
 A bright Chinese blue is produced as follows: 
 
PROPERTIES OF INK-MAKING MATERIALS 43 
 
 70 Ibs. Yellow Prussiate of Potash 
 
 Solution No. 1 > .... , TT , , , . . ., orv0 m 
 (17 '' Hydrochloric Acid 20 Be 
 
 2 45 " Ferrous Chloride 35 Be 
 
 3 f 10i " Hydrochloric Acid 20 Be 
 \ 10 " Potassium Chlorate 
 
 Boil solution No. i till it is neutral and then run it and 
 the 45 pounds of solution No. 2 heated to boiling into a 
 tub of boiling water adding simultaneously solution No. 3, 
 boil with steam until oxidation is complete, wash with 
 water and filter. 
 
 C. Bronze Blue. This is a variety of ferrocyanide 
 blue that shows a metallic luster on drying. It can be 
 made by the following formula: 
 
 Solution No. 1 400 Ibs. Yellow Prussiate of Potash in water 
 
 2 400 " Ferrous Sulphate in water 
 
 3 136 " 36 B6 Nitric Acid 
 
 4 144 " 66 Be Sulphuric Acid 
 
 Heat solutions No. i and No. 2 to boiling and run them 
 simultaneously into a tub of boiling water; run in solu- 
 tions No. 3 and No. 4, boil the entire solution till oxida- 
 tion is complete, wash once and filter. This makes a 
 brilliant blue of strong bronze hue. 
 
 ULTRAMARINE BLUE 
 
 Ultramarine blue is made from a mixture of aluminum 
 silicate, sodium carbonate, sodium sulphate and charcoal. 
 This is calcined in a crucible and ground. The propor- 
 tions vary as regards the hue to be produced and it is 
 very difficult to match a given hue. As the formula for 
 a given hue depends on the composition of the raw ma- 
 terials no attempt to give formulas will be made. 
 
44 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 PROPERTIES OF THE BLUES 
 
 Name 
 
 Top Hue 
 
 Under Hue 
 
 Fineness 
 
 Ultramarine 
 
 Fairly dark 
 
 Fairly light blue 
 
 Very fine impalpable 
 
 blue. 
 
 blue. 
 
 of red hue. 
 
 powder. 
 
 Prussian 
 
 Dark blue. 
 
 Blue of red hue. 
 
 The ferrocyanide blues can 
 
 blue. 
 
 
 
 be either soft or hard depend- 
 
 
 
 
 ing on the method of manu- 
 
 Chinese 
 blue. 
 
 Dark blue. 
 
 Blue of green hue. 
 
 facture and the process of dry- 
 ing. The best of these blues 
 
 
 Dark blue 
 
 
 are the ones that have been 
 
 Bronze 
 blue. 
 
 bronze tone 
 in light. 
 
 Blue of green hue. 
 
 dried soft and feel velvety to 
 the touch. 
 
 Name 
 
 Drying 
 
 Shortness 
 
 Flow 
 
 Ultramarine 
 blue. 
 
 Does not dry well. 
 Has a tendency to 
 rub off. 
 
 Is not short. 
 
 Flows well. Rather long 
 in litho-varnish. 
 
 
 
 
 
 blue 
 
 Ferrocyanide blues 
 
 Fairly short. 
 
 
 
 dry well. They exert 
 
 
 
 Chinese 
 blue. 
 
 a slight drying action 
 themselves but not 
 enough to make them 
 
 Not short. 
 
 All the ferrocyanide 
 blues flow well. 
 
 
 harden in the foun- 
 
 
 
 blue. 
 
 tain or the package. 
 
 Not short. 
 
 
 Name 
 
 Oil Absorption 
 
 Smoothness 
 
 Fastness to light 
 
 Ultramarine 
 blue. 
 
 Rather low. 
 
 Makes a smooth 
 ink. 
 
 Fast to light. 
 
 Prussian 
 
 
 
 
 
 Good. 
 
 
 
 
 
 
 
 Bronze 
 blue. 
 
 Good. 
 
 All ferrocyanide 
 blues make smooth 
 
 All the ferrocyanide 
 blues are fast to light. 
 
 Chinese 
 
 
 
 
 
 Good. 
 
 
 
 blue. 
 
 
 
 
PROPERTIES OF INK-MAKING MATERIALS 
 PROPERTIES OF THE BLUES Continued 
 
 45 
 
 Name 
 
 Atmospheric 
 Influences 
 
 Incompatibility 
 
 Value as an Ink-making 
 Pigment 
 
 Ultramarine 
 
 Darkens somewhat 
 
 Cannot be 
 
 Fair on account of its 
 
 blue. 
 
 on exposure. 
 
 mixed with lead 
 
 poor working qualities on 
 
 
 
 colors. 
 
 the press and its lack of 
 
 
 
 
 distribution. 
 
 
 
 
 Makes a tacky ink with 
 
 
 
 
 varnish and has a tendency 
 
 
 
 
 to print out unevenly. 
 
 
 
 
 Rubs off somewhat after 
 
 
 
 
 drying. 
 
 Prussian 
 blue. 
 
 Chinese 
 blue. 
 
 Bronze 
 blue. 
 
 All the f errocyanide 
 blues turn green on 
 exposure to the at- 
 mosphere due to oxi- 
 dation. 
 
 The ferrocya- 
 nide blues should 
 not be mixed with 
 paris white as they 
 decompose it. 
 For this reason 
 they should be 
 mixed on a 
 straight barytes 
 base. 
 
 With the exception of 
 their change of hue on ex- 
 posure these blues make 
 first-class printing inks and 
 are especially good for 
 toning blacks. 
 On account of price and 
 their deep blue color there 
 are no pigments that can 
 really take their place. 
 
 3. YELLOWS 
 
 CHROME YELLOWS 
 
 These pigments, without doubt the most important 
 and most used mineral pigments, are divided into three 
 classes although they do vary from a light canary yellow 
 through every hue of this color to a red of orange hue. 
 It is customary, however, to class all chromate of lead 
 yellows as either chrome yellows, chrome yellow of orange 
 hue or chrome yellow of red hue and to consider the 
 different modifications as hues of these three. 
 
46 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 In this chapter the first-class or chrome yellows will be 
 taken up, the other varieties being treated under the head 
 of oranges. The chrome yellows are all essentially the 
 normal chromate of lead of the formula PbCrO 4 , the 
 different hues being produced by different processes of 
 manufacture, by which varying amounts of lead sul- 
 phate or carbonate are introduced and different condi- 
 tions of physical structure are produced. Thus the more 
 lead sulphate or carbonate present in the finished product 
 the lighter the pigment produced will be. Different 
 effects will also be produced depending on the size and 
 character of the crystallization. The more crystalline 
 the product is the darker it will be and the less will be 
 its color strength. 
 
 Beginning with chrome yellow, which is the normal 
 chromate of lead, PbCrO 4 , we will therefore find a number 
 of chrome yellows of slightly different hue, growing lighter 
 as the amount of simultaneously precipitated lead sul- 
 phate or unused lead carbonate where white lead is used 
 as a source of lead, increases. 
 
 In the manufacture of these chrome yellows care must 
 be taken to precipitate the color in as nearly the amor- 
 phous condition as possible to insure the proper amount 
 of color strength. This can be done by precipitating the 
 pigment in a very dilute, cold, solution, with constant 
 stirring. The washing should be done as rapidly as pos- 
 sible and the lead and chromate solutions should be run 
 into the tub simultaneously. In order to exactly dupli- 
 cate a hue, care should be taken that the same strength 
 of solution, amount of water, stirring and temperature is 
 used every time. If this is attended to the results of many 
 different batches will duplicate each other very closely. 
 
PROPERTIES OF INK-MAKING MATERIALS 47 
 
 Chrome yellows of different hues are found that con- 
 tain white lead instead of sulphate of lead or mixtures 
 of white lead and sulphate of lead but the authors have 
 found after a long series of tests that the chrome yellows 
 which contain lead sulphate show the least darkening on 
 exposure and have better working qualities. 
 
 A. Chrome Yellow. This is the darkest form of the 
 chrome yellows. It is the normal chromate of lead and 
 has a slight orange hue. 
 
 For the production of a chrome yellow of a good deep 
 yellow with a slight orange hue and of good color strength 
 and of great softness the following formula will be found 
 satisfactory: 
 
 Solution No. 1 100 Ibs. Lead Nitrate to 600 Ibs. water @ 50 F. 
 
 2 35 " Sodium Bichromate to 600 Ibs. water 50 F. 
 
 3 2000 " Water @ 50 F. 
 
 Run No. i and No. 2 simultaneously into No. 3 with 
 constant stirring, let settle, wash and dry in vacuum or 
 at about 160 F. As is seen from the above formula the 
 lead should be somewhat in excess. 
 
 Between the chrome yellow mentioned above and 
 chrome yellow of orange hue there are a variety of yellows 
 of increasing red hue that are produced by the action of 
 sodium or potassium bichromate and monochromate on 
 basic lead acetate. The general way of producing this 
 effect, which is the production of a certain small amount 
 of basic lead chromate along with the normal lead chro- 
 mate, is to neutralize the bichromate with an alkaline 
 carbonate; thus converting part of the salt into the 
 monochromate. These colors being mixtures of basic 
 lead chromate and normal lead chromate should not 
 rightfully be classed as chrome yellows, but they are not 
 
48 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 red enough in hue to be considered as oranges to which 
 class by chemical composition they really belong. 
 
 B. Chrome Yellow Lemon. This is the lightest of 
 the chrome yellows and has a slight green hue. It is 
 variously referred to as primrose yellow, lemon yellow 
 and canary yellow, depending on the lightness of the hue. 
 It is a mixture of normal lead chromate and sulphate or 
 carbonate of lead. The chrome yellow lemon made from 
 white lead is not as stable to light and has not the work- 
 ing qualities for printing inks that the straight sulpho- 
 chromates have and it is preferable in the ink-making 
 business to have a light yellow made with the sulphate 
 alone. 
 
 A formula for making a lemon hued yellow of good 
 color strength, brillancy and fastness to both light and 
 atmosphere is as follows: 
 
 Solution No. 1 100 Ibs. Lead Nitrate to 600 Ibs. water at 50 F. 
 
 2 25 " Sodium Bichromate to 250 Ibs. water @ 50 F. 
 
 3 35 " Sodium Sulphate to 250 Ibs. water @ 50^F. 
 
 4 Mix solutions No. 2 and No. 3 
 
 5 2000 Ibs. water at 50 F. 
 
 Run solutions No. i and No. 4 simultaneously, with con- 
 stant stirring, into solution No. 5, wash well with water 
 and dry at about 100 F. 
 
 As stated before a whole series of hues can be produced 
 between chrome yellow and chrome yellow lemon hue 
 by varying the amounts of bichromate and sodium sul- 
 phate or lead carbonate. 
 
 All lemon hued yellows have a tendency to darken in 
 hue after being made. This difficulty can be overcome 
 by adding a slight excess of sodium carbonate over 
 the amount necessary to neutralize the acid set free in the 
 above process and taking up any excess of soda by the 
 
PROPERTIES OF INK-MAKING MATERIALS 49 
 
 addition of calcium chloride or by neutralizing the acid 
 with freshly precipitated hydrate of alumina. For the 
 above formula 7 pounds of calcium chloride 40 Be and 
 12 pounds sodium carbonate added immediately after 
 the precipitation of the chromate will be found satis- 
 factory. This method of procedure explains why small 
 amounts of calcium carbonate or alumina are found in a 
 great many chrome yellow lemons. 
 
 The lightest chrome yellow lemons, the so-called sul- 
 phur or canary yellows, that have a very green under hue 
 are produced by adding citric or tartaric acid to the bi- 
 chromate solution along with the sodium sulphate. Some 
 color makers hold the theory that the yellow pigments 
 thus made will not darken on exposure to sunlight, but 
 we have found that this is not the case, in fact pigments 
 made with the citrate or tartrate of lead showed more 
 darkening on exposure than those made with the straight 
 sulphate. 
 
 The reason why a chrome yellow made in a very cold 
 solution or with an excess of lead sulphate should stand 
 the light better than any other form of the same chemical 
 composition is not at the present time clear to us and we 
 do not think it advisable to advance a theory in this 
 regard so we will content ourselves with stating a fact 
 that has come under our observation and leave the 
 solution to another time. 
 
CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 PROPERTIES OF THE CHROME YELLOWS 
 
 Normal Lead Chromate and mixtures of Normal Lead Chromate with Lead 
 Sulphate or White Lead and Basic Lead Chromate 
 
 Name 
 
 Top Hue 
 
 Under Hue 
 
 Fineness 
 
 Incompatibility 
 
 Chrome yellow 
 lemon hue. 
 
 Lemon yellow. 
 
 Slightly green. 
 
 
 
 (Normal lead 
 
 There are a 
 
 All of this class 
 
 
 
 chromate with 
 
 number of differ- 
 
 of yellows are dis- 
 
 
 
 lead sulphate or 
 
 ent top hues un- 
 
 tinguished by a 
 
 
 
 white lead.) 
 
 der this class 
 
 more or less 
 
 
 
 
 from a very light 
 
 green under hue. 
 
 
 
 
 sulphur color to a 
 
 
 
 
 
 moderately dark 
 
 
 
 
 
 lemon. 
 
 
 
 
 Chrome yellow. 
 
 
 
 
 
 (Normal chro- 
 
 Deep yellow, 
 
 Slightly red. 
 
 
 
 mate of lead.) 
 
 slightly orange. 
 
 
 
 
 Other modifi- 
 
 There are a 
 
 As these colors 
 
 
 Cannot be 
 
 cations between 
 
 number of hues 
 
 near chrome yel- 
 
 
 mixed with sul- 
 
 the normal lead 
 sulphate and the 
 lead sulpho-chro- 
 mates or mix- 
 
 between chrome 
 yellow of lemon 
 hue and chrome 
 yellow getting 
 
 low they pass 
 from green to 
 yellow and then 
 to red in under 
 
 Good soft 
 colors. 
 
 phur colors or 
 used in the 
 presence of al- 
 kalies. 
 
 tures of normal 
 
 deeper and more 
 
 hue. 
 
 
 
 lead chromate 
 
 orange as they 
 
 
 
 
 and white lead. 
 
 near the normal 
 
 
 
 
 
 lead chromate. 
 
 
 
 
 
 The middle hue 
 
 
 
 
 
 of these is called 
 
 
 
 
 
 chrome yellow 
 
 
 
 
 
 medium. 
 
 - 
 
 
 
 Mixtures of 
 
 There are a 
 
 There are a 
 
 
 
 small amounts of 
 
 number of hues 
 
 number of hues 
 
 
 
 basic lead chro- 
 
 between chrome 
 
 between chrome 
 
 
 
 mates with nor- 
 
 yellow and 
 
 yellow and 
 
 
 
 mal lead chro- 
 
 chrome yellow of 
 
 chrome yellow 
 
 
 
 mate. 
 
 orange hue that 
 
 orange hue that 
 
 
 
 
 are not quite or- 
 
 are progressively 
 
 
 
 
 anges but which 
 
 more red as the 
 
 
 
 
 are more red than 
 
 amount of basic 
 
 
 
 
 chrome yellow. 
 
 lead chromate in- 
 
 
 
 
 
 creases. 
 
 
 
PROPERTIES OF INK-MAKING MATERIALS 
 
 PROPERTIES OF THE CHROME YELLOWS Continued 
 
 Name 
 
 Abrasive 
 Qualities 
 
 Drying 
 
 Shortness 
 
 Flow 
 
 Oil 
 
 Absorption 
 
 Chrome yellow 
 
 
 
 
 
 
 lemon hue. 
 
 
 
 
 
 
 (Normal lead 
 
 
 
 
 
 
 chromate with 
 
 
 
 
 
 
 lead sulphate 
 
 
 
 
 
 
 or white lead.) 
 
 
 
 
 
 
 Chrome yellow 
 
 
 
 
 
 
 (Normal chro- 
 
 
 
 
 
 
 mate of lead.) 
 
 
 
 
 
 
 Other modi- 
 
 
 Dry well. 
 
 
 
 
 fications be- 
 
 
 Not too 
 
 
 
 
 tween the nor- 
 
 
 fast. 
 
 
 
 
 mal lead sul- 
 phate and the 
 lead sulpho- 
 chromates or 
 
 Do not ex- 
 ert any abra- 
 sive quali- 
 ties. 
 
 Drying in- 
 creases as the 
 composition 
 of the yellow 
 
 Have good 
 length in oil 
 or varnish. 
 
 Have good 
 flow. 
 
 Low oil 
 absorption. 
 Work up 
 well in ve- 
 
 mixtures of nor- 
 
 
 nears the nor- 
 
 
 
 hicles. 
 
 mal lead chro- 
 
 
 mal lead chro- 
 
 
 
 
 mate and white 
 
 
 mate. 
 
 
 
 
 lead. 
 
 
 
 
 
 
 Mixtures of 
 
 
 
 
 
 
 small amounts 
 
 
 
 
 
 
 of basic lead 
 
 
 
 
 
 
 chromates with 
 
 
 
 
 
 
 normal lead 
 
 
 
 
 
 
 chromate. 
 
 
 
 
 
 
52 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 PROPERTIES or THE CHROME YELLOWS Continued 
 
 Name 
 
 Smoothness 
 
 Fastness to 
 Light 
 
 Atmos- 
 pheric In- 
 fluences 
 
 Value as an 
 Ink-making 
 Pigment 
 
 Chrome yellow. 
 
 
 
 
 
 Lemon hue. 
 
 
 
 
 
 (Normal lead 
 
 
 
 
 
 chromate with 
 
 
 
 
 
 lead sulphate or 
 
 
 
 
 
 white lead.) 
 
 
 
 
 
 Chrome yellow. 
 
 
 
 
 
 (Normal chro- 
 
 
 - 
 
 * 
 
 
 mate of lead.) 
 
 
 
 
 
 
 
 Not very fast 
 
 
 
 
 
 to light. Darken 
 
 
 
 Other modifi- 
 cations between 
 the normal lead 
 sulphate and the 
 lead sulpho-chro- 
 mates or mix- 
 tures of normal 
 lead chromate 
 and white lead. 
 
 Make smooth 
 inks. 
 
 somewhat on ex- 
 posure. Those 
 colors made with 
 lead sulphate 
 darken less than 
 those without sul- 
 phate. 
 Normal lead 
 chromates do not 
 darken much if 
 
 Sulphur 
 gases in the 
 air affect 
 all chrome 
 yellows. 
 
 Very good on 
 account of the 
 variety of hues 
 and their work- 
 ing qualities. 
 They are an 
 important class 
 of pigments for 
 all kinds of print- 
 ing inks. 
 
 
 
 they are pure 
 
 
 
 
 
 products. 
 
 
 
 Mixtures of 
 
 
 
 
 
 small amounts of 
 
 
 
 
 
 basic lead chro- 
 
 
 
 
 
 mates with nor- 
 
 
 
 
 
 mal lead chro- 
 
 
 
 
 
 mate. 
 
 
 
 
 
PROPERTIES OF INK-MAKING MATERIALS 53 
 
 4. GREENS 
 
 CHROME GREEN 
 
 While there are a number of different mineral greens on 
 the market the only green of any importance to the ink 
 maker is the so-called chrome green, which, in reality 
 is a mechanical mixture of chrome yellow and prussian 
 blue. This green can be prepared in two ways, wet and 
 dry, but only that produced by the wet process is suit- 
 able for printing inks. There are a great many hues of 
 this pigment that can be attained by variations in the 
 process of manufacture and the materials used, so many 
 in fact, that nothing but a general description of the 
 method of making this pigment can be attempted here. 
 
 Chrome green for use in printing inks should be made 
 only from pure chrome yellow and prussian blue without 
 the addition of barytes or any other base except lead 
 sulphate. The chrome yellow should be precipitated 
 first and washed several times and freshly made prussian 
 blue run into it in the form of a thin paste, with constant 
 stirring. The prussian blue best suited for making 
 bright greens is a blue of slight reddish hue about half 
 between a blue of green hue and a blue of decided red hue. 
 
 The different hues of chrome green are produced by 
 varying hues of chrome yellow and different amounts of 
 prussian blue. Thus, when mixed with the proper amount 
 of blue, a chrome yellow of lemon hue will give a bright, 
 light chrome green. While a chrome yellow (normal 
 lead chromate) will give a very dark green. Between 
 these two almost any hue can be produced by varying 
 the amount of blue and using a lighter or darker yellow. 
 Care should be taken not to employ a yellow of decided 
 
54 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 orange hue or a yellow with a red under hue as the resul- 
 tant green will be an olive or a dirty green. The yellows 
 for making chrome greens should always be the lightest 
 and brightest that can be made. 
 
 Some firms have been very successful in making a 
 bright, resistant green by the use of zinc yellow, that is, 
 the chromate of zinc. It has been our experience, how- 
 ever, that this color does not give the working qualities 
 that the lead chromate greens give. 
 
 CHROMIUM OXIDE 
 
 The oxide of chromium is really the best and fastest 
 green that can be secured but it can only be obtained 
 at its best in one hue. It is also a very expensive color, 
 too expensive in fact for general use except as a tinting 
 color or for the highest grades of work. 
 
 PROPERTIES OF CHROME GREENS 
 
 Name 
 
 Top Hue 
 
 Under Hue 
 
 Fineness 
 
 Incompatibility 
 
 Chrome green. 
 
 Varies in top 
 
 Varies from a 
 
 Always fine. 
 
 Incompatible 
 
 
 hue from a light 
 
 light green to a 
 
 
 with sulphur 
 
 
 green to almost 
 
 very dark blue. 
 
 
 colors and al- 
 
 
 black. 
 
 
 
 kalies. 
 
 Chromium 
 
 
 
 
 
 oxide. 
 
 Medium green. 
 
 Medium green. 
 
 Fine. 
 
 Unaffected. 
 
 
 
 Name 
 
 Drying 
 
 Shortness 
 
 Flow 
 
 Oil Absorption 
 
 Chrome green. 
 
 Dries well. 
 
 Makes a long 
 
 Flows well. 
 
 Low, mixes 
 
 
 
 ink. 
 
 
 well with ve- 
 
 
 
 
 
 hicles. 
 
 Chromium 
 
 
 
 
 
 oxide. 
 
 Dries well. 
 
 Long in oils. 
 
 Flows well. 
 
 (Same as above.) 
 
PROPERTIES OF INK-MAKING MATERIALS 
 PROPERTIES OF CHROME GREENS Continued 
 
 55 
 
 Name 
 
 Fastness to 
 Light 
 
 Atmospheric 
 Influence 
 
 Value as an Ink-making 
 Pigment 
 
 Chrome 
 green. 
 
 Fast to light. 
 
 Blues some- 
 what on expo- 
 sure. 
 
 A very valuable pigment on 
 account of its price and stability 
 under all conditions except those 
 of an alkaline nature. 
 
 Chromium 
 oxide. 
 
 Absolutely 
 fast to light. 
 
 Fast to all at- 
 mospheric influ- 
 ences. 
 
 An excellent pigment under all 
 conditions but too expensive ex- 
 cept for the highest kind of work. 
 
 5. ORANGES 
 
 CHROME YELLOW ORANGE 
 
 The chrome yellow oranges, which include all the hues 
 of orange between chrome yellow orange hue and chrome 
 yellow red hue are very important pigments. They are 
 the best mineral oranges for printing-ink work. Chrome 
 yellow orange hue is a mixture of normal lead chromate 
 and basic lead chromate, while chrome yellow red hue is 
 the basic chromate of lead. These hues, which have a 
 very wide range, are produced by increasing the amount 
 of basic lead chromate in the pigment until it finally con- 
 sists entirely of the basic chromate, which is chrome 
 yellow, red hue. 
 
 A. Chrome Yellow, Orange Hue. This is a bright 
 pigment of true orange hue. It is generally made by con- 
 verting part of the normal lead chromate of the chrome 
 yellows into basic lead chromate, by treatment with 
 caustic soda. If normal lead chromate is treated directly 
 with caustic soda there will be a loss of chromium, which 
 goes off in the filtrate as sodium chromate. In the fol- 
 
56 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 lowing method, which gives a bright, soft, pigment of 
 decided orange hue and good color strength, the loss of 
 chromate is avoided, as the sodium chromate formed in 
 the decomposition of the normal lead chromate is used 
 up by the lead sulphate. By varying the amount of 
 sulphate and caustic soda any number of different 
 degrees of orange hue can be obtained. 
 
 Solution No. 1 100 Ibs. Lead Nitrate in 600 Ibs. water 50 F. 
 
 2 18| " Sodium Bichromate in 600 Ibs. water 50 F. 
 
 3 12| " Sulphuric Acid 66 Be" 
 
 4 Solutions No. 2 and No. 3 mixed 
 
 5 2000 " Water at 50 F. 
 
 6 Caustic Soda 40 Be 
 
 Run solutions No. i and No. 4 simultaneously into No. 
 5, decant off the top liquor, heat No. 5 to boiling and 
 add No. 6 until the desired color is reached. 
 
 B. Chrome Yellow, Red Hue. This pigment is basic 
 chromate of lead. It has a dull orange red top hue and 
 an under hue of orange with a slight red hue. It could 
 be classed as a red but on account of its chemical com- 
 position and the decided orange of its under hue it is 
 more properly classed as an orange. 
 
 The following formula will give a good type of this 
 pigment : 
 
 Solution No. 1 100 Ibs. White Lead, well ground in 30 Ibs. of water. 
 
 2 31 " Potassium Bichromate in 110 Ibs. of water, this solution 
 
 being neutralized with ' 281 Ibs. of crystallized 
 Soda. 
 
 3 No. 2 is heated to boiling until the Carbonic Acid is ex- 
 
 pelled and No. 1 is added as slowly as possible. The 
 resultant precipitate is then drawn off into another tub 
 and washed twice. Enough water is then added to 
 make it up to the original volume of the mixed 
 solutions. 
 
 4 Sulphuric Acid 66 Be., about 4 Ibs. to every calculated 
 
 100 Ibs. of Basic Lead Chromate in No. 3. 
 
PROPERTIES OF INK-MAKING MATERIALS 57 
 
 Run No. 4 into No. 3 in the cold with constant stir- 
 ring. The material is then washed once with hot 
 water and dried. 
 
 ORANGE MINERAL 
 
 Orange mineral is another pigment of orange hue; but 
 its value as an ink-making pigment is not nearly so great 
 as that of chrome orange, since it has several very serious 
 physical defects. Orange mineral consists of PbO and 
 PbO 2 chemically combined to make Pb 3 O 4 , in the follow- 
 ing percentages, 35 per cent PbO 2 and 65 per cent PbO. 
 This percentage varies a little in different samples. Three 
 varieties of orange mineral are recognized in the color 
 trade namely, German, French and American. They are 
 all of approximately the same chemical combination, but 
 differ greatly from each other in physical characteristics. 
 This is due entirely to differences in the raw materials 
 used to produce the pigment. 
 
 The most serious drawback to orange mineral is its 
 tendency to form a soap with linseed oil and thus to 
 produce a livery ink, and the fact that an ink made from 
 it will harden so that it is unfit for use after standing for 
 a short while. French orange mineral shows this defect 
 least of the three varieties, while American orange min- 
 eral is on this account practically worthless for printing- 
 ink work. All of the orange minerals settle out badly and 
 show a great many defects in working qualities. The 
 different varieties also have slightly different hues. 
 
 Methods of Manufacturing Orange Minerals. Both 
 French and German orange minerals are made by 
 heating white lead in a muffie furnace until the carbonic 
 acid and moisture are driven off and the resulting lead 
 
CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 oxide converted into the proper proportions of dioxide 
 and monoxide. French orange mineral is made by using 
 white lead made according to the French method while 
 German orange mineral is made from white lead made 
 according to the German method. The American orange 
 mineral, which is nothing but what is ordinarily called 
 red lead of a slight orange hue, is made by heating lith- 
 arge in a muffle furnace. 
 
 PROPERTIES OF THE ORANGES 
 
 Name. 
 
 Top Hue 
 
 Under Hue 
 
 Fineness 
 
 Fastness to 
 Light 
 
 Incom- 
 patibility 
 
 Chrome 
 
 
 
 
 
 
 yellow, 
 
 Bright orange 
 
 Yellow orange 
 
 
 Very Fast. 
 
 
 orange hue 
 
 
 
 
 
 
 Chrome 
 yellow, 
 
 Dull orange 
 
 rprl 
 
 Orange of 
 decided yel- 
 
 
 Very Fast. 
 
 
 red hue. 
 
 led. 
 
 low hue. 
 
 
 
 
 French 
 
 Bright or- 
 
 Bright or- 
 
 
 Darkens 
 
 
 orange 
 mineral. 
 
 ange of slight 
 red hue. 
 
 ange of slight 
 red hue. 
 
 Impalpable 
 powder. 
 
 slightly under 
 light. 
 
 Affected by 
 sulphur colors 
 
 
 
 Bright or- 
 
 
 
 
 German 
 
 Bright or- 
 ange, slightly 
 
 ange with a 
 slight red hue. 
 
 
 Dark ens 
 
 
 orange 
 mineral. 
 
 lighter than 
 the French. 
 
 More yellow 
 than the 
 
 
 slightly under 
 light. 
 
 
 
 
 French. 
 
 
 
 
 American 
 
 Orange of 
 
 Orange of 
 
 
 Darkens 
 
 
 orange 
 
 decided red 
 
 decided red 
 
 
 slightly under 
 
 
 mineral. 
 
 hue. 
 
 hue. 
 
 
 light. 
 
 
PROPERTIES OF INK-MAKING MATERIALS 
 
 59 
 
 PROPERTIES OF THE ORANGES Continued 
 
 Name 
 
 Atmospheric 
 Influences 
 
 Abrasive 
 Qualities 
 
 Oil 
 Absorption 
 
 Drying 
 
 Shortness 
 
 
 
 
 
 Exert con- 
 
 
 Chrome 
 
 
 
 
 siderable dry- 
 
 
 yellow, 
 
 
 
 
 ing action. 
 
 Is of good 
 
 orange 
 
 
 
 
 Care should 
 
 .ength. 
 
 hue. 
 
 
 
 
 3e taken in 
 
 
 
 
 
 
 using driers. 
 
 
 
 
 
 
 Exert con- 
 
 
 Chrome 
 yellow, 
 red hue. 
 
 Affected by 
 sulphur gases. 
 
 Not abrasive. 
 
 Very low. 
 
 siderable dry- 
 ing action. 
 Care should 
 be taken in 
 
 Is of good 
 length. 
 
 
 
 
 
 using driers. 
 
 
 French 
 
 
 
 
 
 
 orange 
 
 
 
 
 Dries quickly. 
 
 Fairly long. 
 
 mineral. 
 
 
 
 
 
 
 German 
 orange 
 mineral. 
 
 
 
 
 Dries very 
 quickly. 
 
 Fairly short. 
 
 American 
 orange 
 mineral. 
 
 
 
 
 Dries very 
 quickly. 
 
 Very short. 
 
60 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 PROPERTIES OF THE ORANGES Continued 
 
 Name 
 
 Flow 
 
 Smoothness 
 
 Value as an Ink-making Pigment 
 
 yellow, 
 
 Good. 
 
 
 Very important. A fairly cheap pig- 
 ment that works well in all kinds of ink. 
 
 orange hue 
 
 
 
 
 Chrome 
 yellow, 
 
 Good. 
 
 
 Used in making mixed or degraded colors 
 where a red top hue and yellow orange 
 under hue is desired. The only pigment of 
 
 red line. 
 
 
 
 this character there is. 
 
 French 
 orange 
 mineral. 
 
 Flows 
 fairly 
 well. 
 
 Very smooth. 
 
 Is not of very much value. But it is the 
 best of the three kinds of orange mineral 
 as it does not thicken as readily as the 
 
 
 
 
 other two. 
 
 German 
 orange 
 
 Flows 
 fairly 
 
 
 Thickens up and livers on standing. 
 Not of much value. 
 
 mineral. 
 
 well. 
 
 
 
 American 
 
 Does not 
 
 
 
 orange 
 
 flow very 
 
 
 Of no value as an ink-making pigment. 
 
 mineral. 
 
 well. 
 
 
 
 6. RUSSETS 
 
 All the inorganic pigments that can be classed as rus- 
 sets owe their hue primarily to iron oxide; the different 
 names met with are either given to them as trade names 
 or to differentiate between various hues. As a rule these 
 iron oxide pigments, whether natural earth pigments or 
 artifically made by precipitation of iron or calcining by- 
 products, have practically no value as typographical ink 
 pigments and very little value as plate ink pigments on 
 account of their hardness, which causes abrasion of the 
 plates in plate printing. Another drawback is the diffi- 
 culty of getting them in a fine state of division, as any 
 slight coarseness makes them fill up the forms in typo- 
 graphic work. 
 
PROPERTIES OF INK-MAKING MATERIALS 6 1 
 
 All of these colors, on account of their low price, are 
 used on cheap poster work but as the same or even better 
 effects can now be produced for high grade work by colors 
 with superior working qualities their work is limited to 
 the above field and to work where an alkaline condition 
 is to be met with, such as wrappers for soap and labels 
 for lye cans. 
 
 INDIAN RED 
 
 Indian red is a clay containing a high percentage . of 
 iron oxide. The general way of preparing it is to levigate 
 the crude color to remove the sand and other impurities, 
 calcine it in a furnace and regrind the calcined product. 
 As can easily be imagined the resulting pigment lacks fine- 
 ness of grain and is generally contaminated with fine sand. 
 
 VENETIAN RED 
 
 Venetian red is an iron oxide pigment made in two 
 ways, either by precipitating a solution of ferrous sul- 
 phate with soda and calcining the precipitate or by cal- 
 cining ferrous sulphate in a muffle and then recalcining 
 the ferric oxide with salt. The hue varies with the 
 amount of salt used. This pigment is a hard grained 
 material seldom of any degree of fineness due to the dif- 
 ficulty of grinding it. 
 
 BURNT UMBER 
 
 Burnt umber is the calcined form of a clay containing 
 iron oxide and manganese, called raw umber. It is some- 
 what similar in physical characteristics to indian red and 
 is treated in the same way. It is rarely very fine, fre- 
 quently contains grit and sand, and is not of much value 
 except for mixing a small quantity in an ink to produce 
 a certain shade. 
 
62 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 BURNT SIENNA 
 
 Burnt sienna is the calcined product of raw sienna, an 
 earth containing a large percentage of ferric hydroxide. 
 It is similar in physical characteristics to the other iron 
 pigments. Its value is about the same as that of umber. 
 
 7. CITRINES 
 
 The pigments that can be classed as citrines are the raw 
 forms of sienna, umber and ochre. They also, as do the 
 russets, owe their hues to varying amounts of iron and 
 manganese oxides. They have little or no value as ink- 
 making pigments. The method of preparing these pig- 
 ments, which is practically the same for all three, 
 consists in levigating, drying and grinding. Care should 
 be taken in drying as these pigments change color at 
 high temperatures. 
 
 PROPERTIES or RUSSETS AND CITRINES 
 
 Name 
 
 Top Hue 
 
 Under Hue 
 
 Fineness 
 
 Incompatibility 
 
 Abrasive 
 Qualities 
 
 
 Dull 
 
 
 
 
 
 Indian 
 red. 
 
 purple 
 
 Dull brown 
 red. 
 
 
 
 
 
 red. 
 
 
 
 
 
 Venetian 
 
 Light 
 brown 
 
 Dull brown 
 
 
 
 
 red. 
 
 red. 
 
 red. 
 
 Coarse. 
 
 Can be used with 
 any color or base. 
 
 Very 
 abrasive. 
 
 Burnt 
 
 Dark 
 
 Dull yellow 
 
 
 
 
 umber. 
 
 brown. 
 
 brown. 
 
 
 
 
 
 Dark 
 
 
 
 
 
 Burnt 
 sienna. 
 
 brown 
 
 Light red 
 brown. 
 
 
 
 
 
 red. 
 
 
 
 
 
PROPERTIES OF INK-MAKING MATERIALS 
 PROPERTIES OF RUSSETS AND CITRINES Continued 
 
 Name 
 
 Drying 
 
 Shortness 
 
 Oil Absorption 
 
 Flow 
 
 Fastness 
 to Light 
 
 Indian red. 
 
 
 
 Quite high. 
 
 
 
 Venetian red. 
 Burnt umber. 
 
 Dries poorly. 
 
 Short. 
 
 Quite high. 
 Very high. 
 
 Poor. 
 
 Fast. 
 
 Burnt sienna. 
 
 
 
 Very high. 
 
 
 
 Name 
 
 Atmospheric 
 Influences 
 
 Smoothness 
 
 Value as Ink- 
 making Pigments 
 
 Indian red. 
 
 
 
 
 Venetian red. 
 Burnt umber. 
 
 Not affected. 
 
 Very grainy. 
 
 Poor. 
 
 Burnt sienna. 
 
 
 
 
 8. BLACK PIGMENTS 
 
 From the point of view of wideness of use and quan- 
 tity used the black pigments are without doubt the most 
 important ink pigments. With but one exception they 
 are all manufactured products and all but two of them 
 owe their blackness to amorphous carbon. The black 
 pigments are practically all good ink-making pigments, 
 different ones being adapted to different classes and pro- 
 cesses of printing; while one or two are valuable as 
 adjuncts, that is as materials to add to certain inks to 
 improve their working qualities. 
 
 The black pigments may be primarily divided into five 
 classes as follows: 
 
64 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 Bone Black. 
 
 Vine Black or Vegetable Black. 
 Carbon or Gas Black. 
 Lamp or Oil Black. 
 
 Miscellaneous Blacks (including natural blacks and certain blacks made 
 by patented processes, from by-products or from mixtures of certain others, that 
 do not fall readily in to the above classifications). 
 
 A. Bone Black. Bone blacks are, as the name 
 implies, made by the calcination of bones in air-tight 
 retorts. They consist essentially of carbon and an ash, 
 consisting of calcium phosophate and calcium carbonate 
 with a small amount of calcium sulphate and sulphide, 
 these salts being the mineral constituents of the bones. 
 This ash amounts to about eighty-five per cent of the 
 black. 
 
 The bone blacks found on the market are of three dif- 
 ferent varieties: sugar-house bone black, that is bone 
 black that has already been used to refine sugar; bone 
 black primarily made for use as a pigment and acid 
 washed bone black. The method of manufacturing the 
 bone black is the same in all cases but on account of the 
 after treatment, the different varieties have different phys- 
 ical properties. 
 
 Method of Making Bone Black. The general process 
 of making bone black is to select the densest bones, boil 
 them to remove the fat, grind to a coarse powder and 
 burn them in retorts from which the air is excluded by 
 luting. In most bone-black factories the by-products of 
 the dry distillation, ammonium carbonate, bone oil, etc., 
 are recovered in a suitable manner. When the bones are 
 thoroughly calcined the retorts are allowed to cool and 
 the product withdrawn. 
 
PROPERTIES OF INK-MAKING MATERIALS 65 
 
 For use in refining sugar the material is left in its gran- 
 ular form. After being used for filtering sugar until its 
 decolorizing power is entirely used up the black is washed, 
 ground wet, dried, bolted and finds its way to the mar- 
 ket as a pigment. 
 
 In preparing bone black for a pigment primarily, the 
 dense hard bones are ground very fine, sifted and then 
 burnt, the products of combustion in most cases being 
 burnt instead of recovered. This, it is claimed, makes a 
 better product than when the by-products are recovered, 
 although it is impossible to see any reason why this 
 should be so. As in many similar cases this appears to 
 be a tradition with no practical foundation. The bone 
 black prepared in this way has greater strength of color 
 and better working qualities than sugar-house bone 
 black. 
 
 When bone black is treated with acid the calcium salts 
 are dissolved out and the result is a very finely grained 
 carbon containing little or no ash, depending on the 
 amount of acid treatment. Acid treated bone black 
 has a very deep black color and in consequence of its 
 fine state of division a great deal of color strength. It is 
 used as a toner for slightly off -colored or weak bone blacks 
 and as a forcing black to bring up the color on certain 
 classes of plate work. As a toner for bone blacks it 
 is far superior to lamp or carbon black on account of its 
 lower oil absorption and its better working qualities. 
 
 The use of bone black is entirely restricted to plate 
 printing inks. Bone black is also designated by the plate 
 printing trade as hard black. It is sometimes put on the 
 market in lumps or in the form of drops, the idea being 
 that blacks in this form are purer and better than the 
 
66 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 powdered blacks; this is of course, a great fallacy as the 
 pigments in both cases are identical. 
 
 B. Vegetable or Vine Black. Under the head of 
 vegetable or vine blacks are classed the black pigments 
 produced by the dry distillation and carbonization of 
 willow wood, wine yeast, grape husks, grape-vine twigs, 
 spent tan bark, shells, fruit pits, sawdust or in fact any 
 material of vegetable origin. 
 
 The blacks made from grape-vine twigs, grape husks 
 and wine yeast are the best of this class and the name 
 vine black is derived from the fact that they were for- 
 merly used exclusively to produce it. Of late years how- 
 ever this name has been extended to take in every variety 
 of black of vegetable origin. These vegetable blacks, 
 when properly made, are of a deep black color and show 
 great strength. They consist of about 75 per cent of 
 carbon and 25 per cent of ash. The ash contains silica, 
 calcium phosphate, carbonate and sulphate and a small 
 amount of potassium carbonate. 
 
 The vegetable blacks can be graded in the following 
 manner: 
 
 True vine black, that is black from wine yeast or 
 grape-vine twigs. 
 
 Blacks from grape husks. 
 
 Blacks from willow charcoal. 
 
 Blacks from spent tan bark. 
 
 Blacks from fruit pits. 
 
 The differences in quality are due entirely to the dif- 
 ferent physical properties exhibited by the products from 
 different sources: such as differences in density, grain and 
 state of division and to the process employed in carboniz- 
 ing them and treatment after carbonization. 
 
PROPERTIES OF INK-MAKING MATERIALS 67 
 
 Method of Making Vine Black. In the manufacture 
 of vine black practically the same process is used as in 
 the manufacture of bone blacks, that is the raw materials 
 are carbonized in the absence of air. This is done in a 
 suitable retort, a number of different forms of apparatus 
 being used, with or without the recovery of by-products. 
 
 After the material is burnt, it is well washed with water 
 to remove the soluble alkaline salts and ground. The 
 very finest grades of vine black are also acid washed, 
 which produces about the same effect as it does in the 
 case of bone blacks. In the plate printing trade in which 
 trade they are only used, they are called soft blacks. 
 Their principal use is to give a certain grain to bone 
 blacks and to give increased color. 
 
 C. Carbon or Gas Black. Carbon or gas blacks are 
 almost pure carbon containing practically no ash. They 
 consist of about 92 to 95 per cent of carbon, the remainder 
 being moisture and unburnt hydrocarbons from the raw 
 material. The amounts of moisture and unburnt hydro- 
 carbons are of course variable with the process of manu- 
 facture and the care taken in collecting the finished 
 product. 
 
 The carbon blacks are very fine pigments of low spe- 
 cific gravity and are consequently very bulky. They are 
 a very deep black and make excellent typographical inks 
 of fine working qualities. They cannot, however, be 
 used in plate inks on account of their high oil absorption 
 and lack of body which makes them hard to wipe or 
 polish. 
 
 There is a wide range in the behavior of different car- 
 bon blacks when made into inks, a wider range than 
 there is any apparent cause for. In working qualities, 
 
68 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 the different brands and grades of carbon black on the 
 market exhibit this to a great extent. They vary from 
 making short, tacky inks to making inks of great natural 
 length and decided flow while some carbon blacks which 
 we have had experience with, were absolutely worthless 
 for making any kind of ink, even news ink. A great 
 difference will also be found in the behavior of different 
 carbon blacks towards driers. The authors have done 
 a great deal of work along these lines but have been 
 unable to find any reason as to why the working qualities 
 and behavior of blacks of the same general origin and 
 composition should vary in their physical properties to 
 such an extent. By the proper combination of varnishes 
 and grades of black almost any desired effect can be pro- 
 duced in typographical printing ink by the use of this 
 pigment. 
 
 Manufacture of Carbon Black. There are numerous 
 different methods of making gas black which are all sim- 
 ilar in the essentials. That of burning natural or some 
 form of producer gas with a small supply of air and col- 
 lecting the soot in a suitable way is the most common. 
 The methods of burning the gas and of collecting the 
 resultant pigment vary greatly, a number of patents hav- 
 ing been granted both in this country and abroad on 
 special apparatus for burning and collecting carbon black. 
 
 The apparatus most commonly in use in this country 
 at the present day consists of a burner, generally ordinary 
 pipe, but in some cases a regular burner of the Argand 
 type, and a water-cooled surface for collecting the soot. 
 This water-cooled surface is rotated above the burner 
 and is provided with a means for removing the soot as it 
 accumulates. The carbon black made in this way is a 
 
PROPERTIES OF INK-MAKING MATERIALS 69 
 
 soft, bulky, deep black product and contains only a small 
 amount of unburnt hydrocarbons. 
 
 D. Lampblack. Lampblacks like carbon blacks are 
 almost pure carbon and are similar in appearance to car- 
 bon blacks with the exception that, as a rule, they are not 
 in such a fine state of division and contain more prod- 
 ucts of distillation. A very fine calcined lampblack, that 
 is one which has been reheated after making, shows about 
 the same properties as carbon black. As is the case in 
 carbon blacks, there are a great many grades of lamp- 
 black on the market, depending on the raw materials 
 used, the methods of manufacture and on the state of 
 division of the product. Each of these grades shows 
 certain different physical properties. 
 
 A number of raw materials have been and still are used 
 for making lampblack, among which, may be noted, 
 naphthalene, anthracene, oil residues, pitch, resin and 
 gas tar oils, the latter being the most widely used at 
 present. Nearly all of the lampblack now on the market 
 is made from the "dead oil" of the gas house. 
 
 There are a number of patents relating to apparatus 
 for burning and collecting lampblack, the process being 
 fundamentally the same as that used in making carbon 
 black. There is, however, a difference in manipulation 
 and in the details of the processes. 
 
 The most used method of producing lampblack is as 
 follows : the material to be burnt is introduced into a 
 cast-iron furnace, fitted with a door for the purpose and 
 containing a pan or receptacle which has been heated to 
 redness. This ignites the material to be burnt and the 
 products of combustion are led into collecting chambers. 
 The furnace is recharged from time to time by ladles, 
 
70 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 care being taken not to allow too much air to enter the 
 furnace during the charging. The heating pans must be 
 changed and cleaned every few days. 
 
 The collecting chambers consist of flues with staggered 
 walls dividing them into compartments. These walls 
 act in a way as baffle plates to stop the passage of the 
 soot particles. The heavier particles will be deposited 
 in the first compartment, while the finer ones are carried 
 through and are deposited at the very end of the collect- 
 ing chambers. The lampblack deposited in the first 
 compartment is large grained and contains quite a large 
 percentage of unburnt hydrocarbons while that collected 
 in the last compartments is in a very fine state of division 
 and is almost pure carbon. In some cases the lampblack 
 collected in these chambers is recalcined in steel drums 
 to rid it of unburnt hydrocarbons and the resultant prod- 
 uct is of almost as fine a grade as carbon black. Of 
 late years carbon black has almost entirely taken the 
 place of lampblack in printing ink. 
 
 . Miscellaneous Blacks 
 
 A. Mineral Black. This pigment is a clay shale 
 containing about thirty per cent of carbon. When prop- 
 erly prepared, that is washed and ground, it forms a fine, 
 soft powder. It is sometimes used in making mixed 
 blacks for plate printing inks. 
 
 B. Manganese Black. The precipitated dioxide of 
 manganese makes a brownish black that is of value when 
 mixed with bone and vine blacks in the preparation of 
 plate printing ink. The admixture of a small amount of 
 this material makes a plate printing ink made from bone 
 and vine black and prussian blue or from a mixed black 
 
PROPERTIES OF INK-MAKING MATERIALS 71 
 
 and prussian blue work better, and reduces the amount 
 of gathering. 
 
 C. Magnetic Pigment. Under the name of mag- 
 netic pigment a very finely divided black oxide of iron, 
 produced by a patented process, is put on the mar- 
 ket. It is useful in black plate inks to give greater 
 density, smoothness, and better working qualities. This 
 material also has a tendency to prevent gathering. 
 
 D. Special Blacks. Blacks for various special pur- 
 poses, particularly for adding to other materials, are made 
 from coke, lignite and certain by-products. The ash 
 and carbon contents vary of course with the raw material. 
 
 E. Mixed Blacks. These are a class of blacks made 
 up from bone blacks of different kinds, vine blacks and 
 combinations of the different miscellaneous blacks men- 
 tioned above with the view of overcoming the defects 
 of straight mixtures of bone and vine blacks. They 
 contain between 30 and 50 per cent of ash, not over 5 
 per cent of which should be insoluble in hydrochloric 
 acid, the remainder being carbon. These mixed blacks 
 should never contain carbon black or lampblack as these 
 materials are too hard to wipe and have too high an oil 
 absorption for use in plate inks for which mixed blacks 
 are only used. 
 
72 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 PROPERTIES OF BLACKS 
 
 Name 
 
 Top Hue 
 
 Under Hue 
 
 Oil Absorption 
 
 Fineness 
 
 Bone black. 
 
 Greenish black. 
 
 Brownish 
 black. 
 
 Fairly low. 
 
 Should be fairly 
 fine, that is, they 
 should still have 
 
 Vine black. 
 
 Greenish black 
 darker than bone 
 black. 
 
 Brownish 
 black. 
 
 Fairly low. 
 
 some grain. 
 
 Carbon black. 
 
 Deep black. 
 
 Brownish 
 black. 
 
 High. 
 
 
 Lampblack. 
 
 Deep black. 
 
 Brownish 
 black. 
 
 High. 
 
 
 Mineral black. 
 
 Brownish black. 
 
 Decided 
 brown. 
 
 Fairly low. 
 
 Should be im- 
 palpable powders. 
 
 Magnetic 
 pigment. 
 
 Brownish 
 black. 
 
 Decided 
 brown. 
 
 Low. 
 
 
 Manganese 
 black. 
 
 Brownish 
 black. 
 
 Decided 
 brown. 
 
 Low. 
 
 
 Name 
 
 Flow 
 
 Shortness 
 
 Fastness to 
 Light 
 
 Atmospheric 
 Influences 
 
 Bone black. 
 
 Flows fairly well. 
 
 Fairly short. 
 
 
 
 Vine black. 
 
 Flows fairly well. 
 
 Fairly long. 
 
 
 
 Carbon black. 
 
 Poor. 
 
 Short. 
 
 
 
 Lampblack. 
 Mineral black. 
 
 Poor. 
 Good. 
 
 Short. 
 Fairly long. 
 
 No effect. 
 
 No effect. 
 
 Magnetic 
 pigment. 
 
 Good. 
 
 Long. 
 
 
 
 Manganese 
 black. 
 
 Good. 
 
 Long. 
 
 
 
PROPERTIES OF INK-MAKING MATERIALS 
 PROPERTIES OF BLACKS Continued 
 
 73 
 
 Name 
 
 Drying 
 
 Smoothness 
 
 Abrasive 
 Qualities 
 
 Incompati- 
 bility 
 
 Bone black. 
 
 
 Does not make a 
 smooth ink. 
 
 Quite abrasive. 
 
 
 Vine black. 
 
 
 Does not make a 
 smooth ink. 
 
 Quite abrasive. 
 
 
 Carbon black. 
 
 Lampblack. 
 Mineral black. 
 
 Exert no 
 drying ac- 
 tion. 
 
 Works up very 
 smooth. 
 
 Works up smooth. 
 
 Does not make a 
 smooth ink. 
 
 Not abrasive. 
 
 Not abrasive. 
 Quite abrasive. 
 
 Mixes with 
 everything. 
 
 Magnetic 
 pigment. 
 
 
 Works up very 
 smooth. 
 
 Not abrasive. 
 
 
 Manganese 
 black. 
 
 
 Works up very 
 smooth. 
 
 Not abrasive. 
 
 
 Name 
 
 Value as an Ink-making Pigment 
 
 Bone black. 
 
 Vine black. 
 
 Carbon black. 
 
 Lampblack. 
 
 Mineral black. 
 Magnetic pigment. 
 Manganese black. 
 
 Of great value as a plate printing ink material although it 
 must be mixed with vine black for color and to give the 
 proper working qualities. 
 
 Of great value as a toner to mix with bone black to give 
 color and working qualities to black plate printing inks. 
 
 The most important typographical black, in fact it is the 
 base of all black typographical inks at the present day. 
 
 Not much used at present as its place has been taken by the 
 cheaper but similar carbon black. 
 
 Used principal] y to mix with other blacks. 
 Used principally to mix with other blacks. 
 Used principally to mix with other blacks. 
 
74 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 The mixed blacks, being mixtures of various amounts 
 of the above pigments, will have properties that vary 
 according to properties and amounts of the different 
 ingredients used in their manufacture. 
 
 9. DILUTENTS 
 
 Under the head of dilutents are classed those pigments 
 that can be used to produce tints of the other pigments. 
 They are of necessity white pigments of great covering 
 power and strength. The principle dilutents used in 
 printing ink manufacture are, zinc white, white lead and 
 lithopone. Of these dilutents the most satisfactory, 
 working qualities and brightness of the tint considered, 
 is zinc white; lithopone comes next, but white lead is a 
 very unsatisfactory tinting pigment. These white pig- 
 ments are also used to make printing inks for special 
 purposes, particularly for use on tin where a white back- 
 ground is necessary for color printing. 
 
 ZINC WHITE 
 
 Zinc white is zinc oxide of the formula ZnO. It is a 
 very soft pigment of a good body and covering power. 
 The process of manufacture consists in roasting either 
 metallic zinc or zinc ore till fumes are given off, burning 
 these fumes in an atmosphere of super-heated air and 
 carbon monoxide which accelerates the oxidation of the 
 zinc and condensing the resulting oxide in suitable cham- 
 bers. As is the case in the preparation of lampblack, 
 the zinc oxide deposited first is coarse and heavy and 
 frequently contains particles of metallic zinc, while that 
 deposited farthest away from the retort or rotary fur- 
 
PROPERTIES OF INK-MAKING MATERIALS 75 
 
 nace is the lightest and finest grade. The different raw 
 materials and the care with which the process is carried 
 out produce the different grades of zinc oxide. 
 
 Zinc oxide can be mixed with any other pigment and 
 is not influenced either by light or atmospheric conditions. 
 
 LITHOPONE 
 
 Lithopone is a mixture of artificial barium sulphate and 
 zinc sulphide. It is a soft white pigment of good cover- 
 ing power, in fact, its covering power is very little inferior 
 to white lead and it can be used with excellent results 
 to form tints, although not quite as valuable in this 
 respect as zinc white, which has superior working qualities. 
 
 Method of Making Lithopone. The following is the 
 general method of manufacturing lithopone. Natural 
 barytes is thoroughly mixed with finely ground lignite 
 in the proportion of about 100 pounds barytes to 38 
 pounds lignite. This mixing is best done by grinding the 
 two materials together in the wet way, as the yield of 
 barium sulphide depends to a great extent on the inti- 
 macy of this mixture. The mixture is then dried and 
 put into fireclay retorts with air-tight covers, the retorts 
 themselves being provided with suitable outlets for the 
 products of combustion. These retorts, which are gen- 
 erally arranged in batteries, are heated from the outside. 
 The reduction of barium sulphate takes about four hours 
 and the material in the retorts should be turned after 
 about half this time. The turning should be done rapidly 
 to prevent reoxidation of the barium sulphide which 
 takes place very readily at high temperatures. When 
 the reduction is complete the barium sulphide is dumped 
 into air-tight iron boxes to cool. Care should be taken 
 
76 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS' 
 
 to have as pure barytes as possible, as impurities will 
 have an injurious effect on the resulting lithopone. 
 
 The barium sulphide is then dissolved in water and a 
 solution of zinc sulphate free from iron is made. These 
 two solutions, the strength of each being known, are run 
 into each other in approximately molecular proportions. 
 There should, however, be an excess of zinc sulphate. 
 The precipitate is washed and dried, calcined in retorts 
 until cherry red and quenched suddenly in cold water, 
 after which it is ground in wet mills for a long time, 
 pressed, dried and reground dry. 
 
 Lithopone varies in the amount of zinc sulphide, the 
 larger the amount the better will be the product. Brands 
 of lithopone on the market show a variation in the 
 amount of zinc sulphide from 15 to 33 per cent. 
 
 WHITE LEAD 
 
 White lead is a mixture of basic lead carbonate and 
 lead hydrate with the formula 2 PbCO 3 PbH 2 O 2 . As white 
 lead is of little value as an ink-making pigment and the 
 general methods of its production are well known, a 
 brief explanation of the differences between the French 
 and German methods of preparation is all that will be 
 given here. The German process depends on the corro- 
 sion of metallic lead by acetic acid, the action being 
 accelerated by heat, and the conversion of the basic lead 
 acetate into lead carbonate by the introduction of car- 
 bonic acid gas into the acetic acid vapors. The French 
 process consists in treating a solution of basic lead acetate 
 with carbon dioxide. 
 
 French and German white leads show different char- 
 acteristics; that made by the German process, showing 
 
PROPERTIES OF INK-MAKING MATERIALS 
 
 77 
 
 more covering power but being inferior in whiteness and 
 brillancy to the French. German white lead also has 
 less oil absorption. These differences are partly due to 
 physical structure and partially to varying proportions 
 of lead hydroxide and carbonate. 
 
 PROPERTIES OF DILUTENTS 
 
 Name 
 
 Fineness 
 
 Covering Power 
 
 Strength 
 
 Incompatibility 
 
 White 
 lead. 
 
 
 Very great. 
 
 Great. 
 
 Cannot be used 
 with sulphur colors. 
 
 Litho- 
 pone. 
 
 Impalpable 
 powder. 
 
 Fair. 
 
 Fair. 
 
 Cannot be used 
 with lead colors. 
 
 Zinc 
 white. 
 
 
 Good. 
 
 Good. 
 
 Can be used with 
 any color. 
 
 Name 
 
 Fastness to 
 Light 
 
 Atmospheric 
 Influences 
 
 Oil 
 Absorption 
 
 Flow 
 
 White 
 lead. 
 
 Yellows on ex- 
 posure to light. 
 
 Blackens in air 
 due to sulphur 
 gases. 
 
 Low. 
 
 Good. 
 
 Litho- 
 pone. 
 
 Darkens on ex- 
 posure to light. 
 
 Affected some- 
 what. 
 
 Fairly low. 
 
 Good. 
 
 Zinc 
 white. 
 
 Does not change. 
 
 Not affected. 
 
 Low. 
 
 Fairly good. 
 
78 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 PROPERTIES OF DILUTENTS Continued 
 
 Name 
 
 Shortness 
 
 Smoothness 
 
 Abrasive 
 Qualities 
 
 Value as a Dilutent 
 
 White 
 
 Fairly long. 
 
 Makes a 
 
 
 Not of much value. 
 
 lead. 
 
 
 smooth ink. 
 
 
 Chalks through when 
 
 
 
 
 
 used as a dilutent. 
 
 Litho- 
 
 Fairly long. 
 
 Makes a 
 
 
 Can be used in 
 
 pone. 
 
 
 smooth ink. 
 
 
 both plate and typo- 
 
 
 
 
 
 graphic ink. Mix- 
 
 
 
 
 
 tures of aluminum 
 
 
 
 
 Not abrasive. 
 
 hydrate and zinc 
 
 
 
 
 
 white give better re- 
 
 
 
 
 
 sults in typographic 
 
 
 
 
 
 work. 
 
 Zinc 
 
 Quite long. 
 
 Very smooth. 
 
 
 Of exceptional val- 
 
 white. 
 
 
 
 
 ue for making tints 
 
 
 
 
 
 and on account of 
 
 
 
 
 
 its working qualities 
 
 
 
 
 
 in both plate and 
 
 
 
 
 
 typographic inks. 
 
 
 
 
 
 The best of the 
 
 
 
 
 
 white pigments. 
 
 10. BASES 
 
 In the manufacture of printing inks there is a class of 
 pigments that are of no value as pigments when used by 
 themselves, but form a very important group when used 
 with other pigments. These pigments are what are 
 known as bases. That is, they are used to give body to 
 and to carry other pigments. The bases have very little 
 or no coloring power of their own but impart to the pig- 
 ments they are used with, working qualities and body. 
 They are in a few instances also used to produce tints. 
 
PROPERTIES OF INK-MAKING MATERIALS 79 
 
 The bases are used for a number of different purposes 
 and to produce a number of different results as is shown 
 by the following examples: for instance, in cases where a 
 pigment shows a high oil absorption the mixture of a 
 base of low oil absorption will often overcome this defect. 
 A certain amount of base added to a pigment which in 
 itself is quick drying will sometimes make an ink of 
 moderate drying qualities. In plate printing work the 
 defect of striking through, gathering, softness and sticki- 
 ness can often be overcome by the use of a proper base. 
 The bases are also extensively used as carriers for the 
 organic dyes in the manufacture of lakes. 
 
 The principal bases are barytes (natural barium sul- 
 phate) blanc fixe (artifical barium sulphate), paris white 
 (calcium carbonate), aluminum hydrate, magnesium car- 
 bonate and calcium sulphate. Of these aluminum hy- 
 drate, blanc fixe and magnesium carbonate are the only 
 ones which are of value in typographical inks. 
 
 BARYTES 
 
 The natural sulphate of barium is found more or less 
 purely in almost all parts of the world. It is mined, 
 separated into classes according to its whiteness and 
 ground. Barytes requires a great deal of grinding to 
 reduce it to the proper fineness and the best varieties 
 are water floated after grinding. In a great many in- 
 stances a small amount of ultramarine blue is added to 
 the product to heighten its whiteness. This is frequently 
 done when the material is contaminated with iron, the 
 blue destroying the red or yellow hue imparted by the iron. 
 
 Barytes is a heavy white mineral of a specific gravity 
 between 3.9 and 4.5. It is absolutely indifferent to all 
 
8o CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 other chemicals, even acids, and can only be decomposed 
 by fusion with alkalies. It has very little covering 
 power and can, therefore, be added to other pigments 
 without affecting their strength, and, having a low oil 
 absorption, it is of great value when mixed with pig- 
 ments which absorb a great deal of oil or varnish. On 
 account of its density and grain, barytes, when mixed 
 with pigments for plate inks, overcomes a great many 
 of the defects in working qualities inherent in many 
 mineral pigments; particularly is this true of the chrome 
 colors which are of little value as plate inks by themselves. 
 For fine work the barytes should always be added in 
 the manufacture of the ink itself and not as an adulter- 
 ant in the dry color. Water floated barytes is superior 
 for plate inks to blanc fixe because of its grain which 
 makes the ink wipe clean and polish well. Very finely 
 ground barytes is also of great value as a base for organic 
 lakes. The character of the dye and the method of pre- 
 cipitation exert a great influence on the value of barytes 
 as a lake carrier. 
 
 PARIS WHITE 
 
 Paris white is practically pure calcium carbonate. It 
 is prepared by levigating chalk with water to remove 
 grit and other physical impurities. Chalk, being an 
 amorphous form of calcium carbonate, makes a far 
 better base than ground limestone. 
 
 Paris white is a soft pigment with a specific gravity of 
 about 2.5. It has very little covering power and dries 
 quite slowly. It is generally mixed with barytes in plate 
 inks to improve the polishing and is used to some extent 
 in making organic lakes. 
 
PROPERTIES OF INK-MAKING MATERIALS 8 1 
 
 ALUMINUM HYDRATE 
 
 Aluminum hydrate is a very important base both for 
 printing inks and organic lakes. When added to plate 
 inks it makes them work better, particularly in the 
 polishing. In typographic inks it increases the length 
 and flow, correcting any tendency to shortness and unequal 
 distribution. It is also used with good effect in inks that 
 dry too much themselves, acting in these cases like a 
 reducer. Inks that do not grind up smooth are also 
 helped by the addition of aluminum hydrate. 
 
 Aluminum hydrate has the formula A1 2 (OH) 6 , but most 
 of the commercial aluminum hydrate consists of a mix- 
 ture of basic aluminum sulphate and aluminum hydrate. 
 This condition arises from the fact that basic aluminum 
 sulphate is not very readily converted by sodium car- 
 bonate into aluminum hydrate in cold solutions and it is 
 necessary to precipitate the hydrate in cold solutions in 
 order to get a soft and powdery product on drying. 
 Aluminum hydrate precipitated by alkaline carbonates 
 in hot solutions dries hard and horny. Therefore, when 
 precipitation takes place in the cold a part of the basic 
 aluminum sulphate formed in the process is left uncon- 
 verted. 
 
 The method of manufacturing aluminum sulphate is 
 as follows: 
 
 The solution of aluminum sulphate is treated with an 
 excess of sodium carbonate with rapid stirring until the 
 carbonic acid ceases to be evolved. It is then washed 
 and dried. This process as stated above gives a su- 
 perior product when dried than when the solution is 
 boiled. 
 
82 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 BLANC FIXE 
 
 Blanc fixe, which is the artificial sulphate of barium, is 
 prepared from barytes by calcining finely ground barytes 
 with powdered coal and dissolving the resultant barium 
 sulphide in hydrochloric acid by which process barium 
 chloride is obtained. The amount of barium chloride 
 in the solution is determined by its gravity. It is pre- 
 cipitated by a weak solution of sulphuric acid or sodium 
 or magnesium sulphate in the exact quantity to use up 
 all the barium chloride. When sulphuric acid is used, 
 the solution must be mixed cold, but when sulphates are 
 used it is best to conduct the operation hot as a better 
 filtering product is obtained under these conditions. 
 
 Blanc fixe is in a great deal finer state of division than 
 the natural sulphate and lacks its grain, a quality which 
 is of great value in plate inks. When used as a base for 
 organic pigments blanc fixe is generally precipitated sim- 
 ultaneously with the coloring matter, using a solution of 
 barium chloride and a soluble sulphate. 
 
PROPERTIES OF INK-MAKING MATERIALS 
 
 PROPERTIES OF BASES 
 
 Name 
 
 Fineness 
 
 Covering 
 Power 
 
 Incompatibility 
 
 Fastness 
 to Light 
 
 Oil Ab- 
 sorption 
 
 Natural 
 
 When water 
 
 Fair. 
 
 Mixes well with 
 
 
 Low. 
 
 barytes. 
 
 floated it is 
 
 
 everything. 
 
 
 
 
 fairly fine. 
 
 
 
 
 
 Paris 
 
 Somewhat 
 
 Practically 
 
 With colors that 
 
 
 Fairly low 
 
 white. 
 
 coarse. 
 
 none. 
 
 have a trace of acid 
 
 
 
 
 
 
 paris white will 
 
 
 
 
 
 
 cause swelling, e.g. 
 
 
 
 
 
 
 Prussian blues. 
 
 Fast. 
 
 
 Blanc fixe. 
 
 Impalpable 
 
 Fair. 
 
 Mixes with every- 
 
 
 Fairly 
 
 ^ 
 
 powder. 
 
 
 thing. 
 
 
 high. 
 
 Aluminum 
 
 Impalpable. 
 
 Practically 
 
 Mixes well with 
 
 
 Very high. 
 
 hydrate. 
 
 
 transparent. 
 
 everything. 
 
 
 
 Magnesium 
 
 Impalpable. 
 
 Practically 
 
 Mixes well with 
 
 
 Very high. 
 
 carbonate. 
 
 
 none. 
 
 everything. 
 
 
 
 Name 
 
 Atmospheric 
 Influences 
 
 Shortness 
 
 Flow 
 
 Smoothness 
 
 Abrasive 
 Qualities 
 
 Natural 
 barytes. 
 
 
 Fairly long. 
 
 Fair. 
 
 Grainy. 
 
 Somewhat 
 abrasive. 
 
 Paris white. 
 
 
 Is short. 
 
 None. 
 
 Fairly smooth. 
 
 Slightly 
 abrasive. 
 
 Blanc fixe. 
 
 Is not af- 
 fected. 
 
 Fairly short. 
 
 Good. 
 
 Very smooth. 
 
 Not 
 abrasive. 
 
 Aluminum 
 hydrate. 
 
 
 Very long. 
 
 Fairly 
 good. 
 
 Very smooth. 
 
 Not 
 abrasive. 
 
 Magnesium 
 carbonate. 
 
 
 Fairly long. 
 
 None. 
 
 Very smooth. 
 
 Not 
 abrasive. 
 
CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 PROPERTIES OF BASES Continued 
 
 Name 
 
 Softness 
 
 Value as a Base in Ink and Color Making 
 
 Natural barytes 
 Paris white. 
 Blanc fixe. 
 
 Aluminum 
 hydrate. 
 
 Magnesium 
 carbonate. 
 
 Not very soft. 
 
 Not very soft. 
 
 Very soft. 
 
 Sometimes 
 very soft and 
 sometimes hard 
 and horny. 
 
 Only the soft 
 hydrate should 
 be used. 
 
 Very soft. 
 
 Very valuable as a base for plate inks. 
 Valuable principally as a base for plate inks. 
 
 Valuable as a base in typographic inks and 
 as a carrier for lakes. 
 
 Exceptionally valuable as a base for typo- 
 graphic inks and for a carrier in organic lakes. 
 It is also useful in plate printing inks. 
 
 Is used principally as a base in lithographic 
 and offset inks. 
 
 11. ORGANIC LAKES 
 
 The organic lakes consist of a dye and a base or carrier. 
 There are three general ways of making these lakes, all 
 other methods, except in some special cases, being modifi- 
 cations of these three. 
 
 In the first method the dye solution is mixed and pre- 
 cipitated simultaneously with the base and then fixed. 
 
 In the second method the dye is precipitated on the 
 base which has already been made and then fixed. 
 
 In the third method, generally used in the case of the 
 insoluble or pulp colors, the dye in the form of a water 
 paste and the base are mechanically mixed together by 
 grinding. 
 
 In these different methods the hue of the color can be 
 varied by using different strengths of solutions, different 
 
PROPERTIES OF INK-MAKING MATERIALS 85 
 
 temperatures, different amounts of grinding and in some 
 cases different precipitating or fixing agents. Of course 
 for the various classes of dyes various precipitating agents 
 are employed and it is a little beyond the scope of this 
 work to enter into details regarding them. The general 
 methods of precipitating and preparing these different 
 classes of lakes, however, are as follows: 
 
 In the first case a solution of a certain salt of the 
 carrier is made, the dye mixed in and the precipitating 
 agent added with constant stirring. Thus in the case of 
 a dye to be made on an aluminum hydrate and artifical 
 barytes base, a solution of aluminum sulphate is made 
 and a solution of calcined carbonate of soda is run into 
 it, followed by the dye solution. Barium chloride is 
 then added to the whole and the dye is precipitated and 
 fixed. The more stirring the lake is given at this point 
 the firmer it will be fixed. If, however, there is any 
 unprecipitated coloring matter, more barium chloride is 
 added. It is usual to add the precipitating agent hi 
 excess, as an excess helps in fixing the dye. 
 
 The different hues of these and the second class of 
 lakes also are obtained by a variety of methods jealously 
 guarded by the various manufacturers, the most common 
 of which are different strengths of solution, different 
 temperatures either of the precipitating solution or of 
 the solution after precipitation and by mixing a small 
 amount of another dye in the solution. The first two 
 of these methods also exert an influence on the working 
 qualities of the lake, as the temperature and strength 
 of the solutions have a great deal of influence on the 
 physical characteristics of the base. 
 
 In the second case the carrier is made into a thin 
 
86 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 paste with water, the dye solution added and, after a 
 thorough mixing, the precipitating solution is run in. 
 Some of these lakes, notably those precipitated with 
 tannin, require the use of a fixative such as tartar 
 emetic. 
 
 The third class comprises the insoluble azo colors, 
 which are generally sold in the form of a paste or pulp. 
 These dyes can be ground directly into the carrier on the 
 mill or the dye and carrier can be mixed to a thin con- 
 sistency and stirred into each other, barium chloride 
 added and the whole boiled. This develops certain 
 changes of hue in some cases and also serves to fix the 
 dyes that are at all soluble in water. Of course where 
 desired the base may be precipitated at the time the dye 
 is poured in. In some cases the dye will not stand boil- 
 ing with barium chloride so that the precipitation must 
 be made in the cold. The use of calcium chloride and 
 lead acetate as developers instead of barium chloride will 
 give variations in the hues of certain colors. 
 
 An advantage that these pulp colors also have is that 
 they can be mixed with the proper base and varnishes 
 and ground directly into printing ink on a roller mill, 
 the water being pressed out in the grinding. In plate 
 printing inks the question of the base for organic lakes 
 is not of great importance but for typographic inks, only 
 those lakes made on a precipitated base, such as alumi- 
 num hydrate, blanc fixe, lithopone, etc., should be used. 
 A full discussion of the various bases and their value as 
 ink-making materials will be found in a preceding chapter. 
 In general the precipitating agents employed in manu- 
 facturing organic lakes are barium chloride, lead" salts, 
 aluminum oxide, tin salts and tannic acid. 
 
PROPERTIES OF INK-MAKING MATERIALS 87 
 
 In the past very nearly all the organic lakes, that were 
 not to a great extent soluble in oil varnish, were used 
 as printing ink colors and many, even those bleeding in 
 oil and being fugitive to light, which should have barred 
 them entirely, were used. This was especially true of 
 aniline lakes which even now for this reason bear a very 
 bad reputation in regard to fading and bleeding. The 
 wide use of these inferior lakes was in great part due to 
 their superior working qualities and to the fact that they 
 gave bright and fiery colors and hues that could not be 
 duplicated or even approximated in the available mineral 
 pigments. 
 
 The use of these unsuitable lakes is now rapidly 
 decreasing, and their place has been taken by the per- 
 manent non-bleeding lakes, most of which are made 
 from insoluble azo dyes. As a rule all the lakes made 
 from diazo-dyes, whether the dye is soluble or not, are 
 permanent both to light and atmospheric conditions and 
 do not dissolve in any of the mediums used in printing. 
 These colors are in fact more permanent than any of the 
 mineral colors and are infinitely superior to them in 
 working qualities. They can be obtained moreover in 
 almost every color and hue. The organic lakes can also 
 be made to give a series of very transparent inks, a thing 
 impossible with the mineral colors. 
 
 Inks made from the organic lake pigments are abso- 
 lutely essential to the three-color process, as the colors 
 necessary to produce a properly blended print, from the 
 three plates, in which all the lights and shades have their 
 true color value, can only be made from these pigments; 
 there being no mineral pigments that will give the proper 
 hues of red, yellow and blue. 
 
88 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 It is almost impossible, in view of the fact that these 
 lakes are sold under different trade names by the various 
 manufacturers and jobbers, to give any list of colors that 
 would be suitable for use and the only method open to 
 the printing ink chemist in determining the value of a 
 lake is to determine if possible the dye used in making 
 the lake, what the base of the lake is and to practically 
 try out the lake itself for fading, bleeding and working 
 qualities under the scheme already outlined. 
 
 An illustration of the difficulties in the way of giving 
 any definite tables or descriptions of the different lakes 
 is shown by the fact that lakes of the same color and hue 
 made from the same dye will be found on the market 
 under perhaps a half a dozen different trade names or 
 numbers. Thus a red called "Scarlet Lake" by one 
 manufacturer may be exactly like the " Brilliant Scarlet" 
 of another manufacturer. On the other hand there is 
 no assurance that the lakes sold by two manufacturers 
 under the same name will be the same hue or even if 
 they have the same color and hue approximately, it does 
 not follow that they have been made from the same dye 
 or in the same manner. One of the lakes may be satis- 
 factory in every respect, while the other may be a very 
 poor color. 
 
 SECTION TWO. OILS 
 
 LINSEED OIL 
 
 While there has been a great deal of literature written 
 concerning linseed oil, there is still much work to be done 
 in order to give the technical chemist engaged in manu- 
 facturing and using it, a broad enough knowledge for 
 him to do his work to the most economical advantage. 
 
PROPERTIES OF INK-MAKING MATERIALS 89 
 
 There are very many problems that are constantly arising 
 in practical work with linseed oil, to solve which, the tech- 
 nical chemist must blindly grope and there are many 
 questions purely chemical relating to the testing and 
 identification of this material that are at present mys- 
 teries. The old system of constants has proved entirely 
 inadequate to differentiate between oils treated by air 
 blowing or ageing, and adulterated oils. Further there 
 are no definite ways of determining the specific nature of 
 the adulteration even if adulteration can be proved as 
 existing. 
 
 The authors have done a great deal of work along these 
 lines but as the field has proven to be so broad they can- 
 not, at this time put forth any theories or deductions; 
 they are, however, convinced that the constitution of 
 linseed oil is far more complex and is affected by many 
 more conditions than the investigators heretofore have 
 imagined. 
 
 Linseed oil comes on the market in a number of dif- 
 ferent grades depending on the quality of the seed, the 
 climatic conditions under which the seed was grown, the 
 amount of admixture of foreign seed, the process of extrac- 
 tion, the length of time it has been stored, the method of 
 treatment if the oil has been refined, and the honesty of 
 those who have handled it either as crushers or jobbers. 
 These conditions cause the physical and chemical con- 
 stants of the oils produced to vary greatly and also affect 
 their behavior when used for various purposes. The 
 wide variation in chemical and physical constants from 
 the above causes, coupled with the introduction of cer- 
 tain drying oils which have lately come on the market, 
 and new methods of treating non-drying oils, has made 
 
go CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 it very difficult to determine positively whether an oil 
 has been adulterated or not. 
 
 The accepted constants for raw linseed oil are as 
 follows: 
 
 Not under .931 
 Not under 170 
 
 Specific Gravity 
 Iodine Value 
 
 Saponification Number 
 Flash 
 
 About 190 
 
 Not under 280 C. 
 
 As stated before, the constants are influenced by a 
 number of things and the fact that an oil meets the 
 above requirements, or even falls below them to some 
 extent, is no criterion either of its purity or of its adul- 
 teration. 
 
 The simple treatment of blowing air through the oil at 
 a temperature of about 100 C. changes these constants 
 and at the same time changes the odor and color of the 
 oil completely. Absolutely pure, raw linseed oil blown 
 at 100 C. without any addition of drier or other treat- 
 ment, has failed to pass the above specification while a 
 fresh pressed oil adulterated with soya bean oil and one 
 adulterated with blown rape seed oil have been found to 
 meet these requirements. The following table shows the 
 result of blowing a pure linseed oil direct from the 
 crusher. 
 
 
 Before 
 blowing 
 
 Blown for 
 4hrs. 
 
 Blown for 
 18 hrs. 
 
 Blown for 
 27 hrs. 
 
 Specific Gravity 
 
 .9355 
 
 .9360 
 
 .940 
 
 .946 
 
 Iodine Value 
 
 184.5 
 
 181.4 
 
 1794 
 
 161 6 
 
 Acid Value 
 Saponification Number 
 Flash 
 
 1.0 
 193.2 
 282 
 
 1.18 
 193.3 
 284 
 
 1.18 
 192.9 
 282 
 
 1.18 
 192.7 
 280 
 
 
 
 
 
 
PROPERTIES OF INK-MAKING MATERIALS 
 
 The viscosity was of course increased in proportion. 
 
 The figures given below are those of oils adulterated 
 in one case with 10 per cent of blown rape seed oil and 
 in the other case with 20 per cent of soya bean oil: 
 
 
 Oil as 
 received 
 
 With 10% 
 blown rape 
 seed oil 
 
 Oil as 
 received 
 
 With 20% 
 soya bean 
 oil 
 
 Specific Gravity 
 
 .9356 
 
 9378 
 
 9325 
 
 931 
 
 Iodine Value 
 
 1784 
 
 170 
 
 181 3 
 
 1706 
 
 Acid Value 
 
 1 53 
 
 2 2 
 
 90 
 
 93 
 
 Saponification Number 
 Flash. . 
 
 194.3 
 295 
 
 194.8 
 295 
 
 193 
 296 
 
 192.7 
 295 
 
 
 
 
 
 
 The separation of a flocculent mass on heating an oil 
 to between 270 C. and 300 C., known as breaking, has 
 been found by the authors to be a very erratic thing. 
 Rapidity of heating is a great factor; an oil heated in a 
 test tube where the rise is very rapid will show a break 
 whereas the same oil heated slowly will not. All raw 
 linseed oils, if heated rapidly enough, can be made to 
 show a break even though the oil is bright and clear 
 and has been allowed to settle for six months. The 
 breaking can, however, be eliminated even from a freshly 
 pressed oil by simply warming the oil at 75 C. for a 
 couple of hours. This heating is attended by no change 
 in the physical or chemical constants of the oil. 
 
 As a general rule raw linseed oil will separate out a 
 flocculent precipitate on being chilled which will disappear 
 on warming. When oil has been heated to 100 C. and 
 air blown through it, this separation does not take place 
 on chilling. 
 
 Raw linseed oil, as it comes from the crusher is not 
 
92 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 well adapted to the economical manufacture of printing 
 ink varnishes. All raw linseed oils to be so used, should 
 be subjected to a previous treatment. The most satis- 
 factory treatment has been found to be the blowing of the 
 oil, heated to 100 C., with air. This treatment will 
 produce a fine, clear, odorless oil of high viscosity and 
 gravity and is attended with no loss of weight. The 
 method of blowing is merely to raise the oil to 100 C. 
 by means of a steam jacketed kettle or steam coil, and as 
 this temperature is easily reached, exhaust steam should 
 be used for economical reasons. The air is then blown 
 through the oil in a number of fine jets until the oil has 
 reached the proper viscosity which we have found to be 
 between 1600 and 2000 on an Engler viscosimeter, water 
 being taken as 100. 
 
 Oil of this viscosity will take much less time to boil 
 or burn to the different grades of plate and varnish oils 
 and will show far less loss in the burning or boiling. A 
 comparison between the loss of weight and time of burn- 
 ing to medium plate oil between an unblown oil and the 
 same oil blown to a viscosity of 1600 is herewith given: 
 
 
 Unblown Oil 
 
 Blown Oil 
 
 Viscosity at start 
 
 747 
 
 1600 
 
 Time of burning 
 
 40 minutes 
 
 20 minutes 
 
 Loss in weight 
 
 18% 
 
 6% 
 
 
 
 
 These oils were burnt to the same viscosity and gravity. 
 The raw oil used was of a light yellow color, with consider- 
 able turbidity and a heavy malt odor, while the blown oil 
 was of a rich mahogany color without turbidity or odor. 
 The burnt oil made from the unblown oil was of a greenish 
 
PROPERTIES OF INK-MAKING MATERIALS 93 
 
 color, full of soot, while that made from the blown oil was 
 of a reddish cast, approximately free from carbon. This 
 treatment of the raw oil has been found entirely sufficient 
 and no other treatment is recommended. The color of 
 the oil after blowing we have found to vary greatly, some 
 oils becoming very light in this treatment while others 
 darken considerably, this being no doubt due to the 
 different sources of seeds. 
 
 LINSEED PLATE OILS 
 
 In making printing ink vehicles, two methods may be 
 pursued; namely boiling and burning the oil to the 
 proper consistency. If oil is blown long enough it will 
 become the proper consistency but practical trials of plate 
 printing oils made in this way have shown that the oil so 
 made is not satisfactory, having a false body and being 
 too soft. The results obtained by blowing are purely 
 the results of oxidation while the authors have proved 
 that both oxidation and polymerization are necessary to 
 make a satisfactory working plate ink oil or varnish 
 and that this result is only obtained by the use of high 
 temperature. Heavy blown oils are, however, used to a 
 large extent in typographic inks. 
 
 Plate oils are generally made in three consistencies, 
 strong, medium and weak, and require less tack and 
 length than typographic va'rnishes and yield no gloss 
 on drying in the ink. They are therefore made from 
 linseed oil alone without other additions. Since the be- 
 ginning of the art, the oils for use in plate inks have 
 been burned in iron pots to the desired thickness in the 
 following manner. 
 
 The oil is put in an iron pot holding about 5 gallons 
 
94 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 and heated to about 160 C. It is then ignited by means 
 of a red hot ladle and allowed to burn with enough 
 stirring to thoroughly mix the oil and to keep the heat 
 from becoming excessive; too much - stirring will, how- 
 ever, extinguish the pot. The time required to burn 
 light oil is about 15 to 20 minutes, depending on the 
 initial viscosity of the oil. Medium oil is burnt from 
 25 to 45 minutes, while the heavy or strong oil is 
 burnt from 2 to 3 hours. On account of the length of 
 time required for the burning of this strength of oil and 
 the consequent heat developed, the burner has to keep 
 the heat down by adding from time to time small amounts 
 of cold oil. 
 
 The light oil loses in this process from 5 per cent to 
 10 per cent of its weight; the medium oil from 8 per cent 
 to 1 8 per cent and the strong oil from 18 per cent to 
 25 per cent. As can readily be seen, this great loss is 
 principally due to the use of the oil itself as a fuel, which 
 is a very costly process. It has always been traditional 
 that this burning was necessary to burn the grease out 
 of the oil; and the belief was founded, no doubt, on the 
 fact that a burnt oil will not leave a grease mark on 
 paper. This is, of course, due to the fact that burnt 
 oils have a higher viscosity and gravity and do not spread 
 and penetrate the fibers of the paper. 
 
 The burning of the oil is not at all necessary and the 
 polymerization and oxidation required can be effected 
 as well by outside heat, by rapidly raising the tempera- 
 ture of the oil to about 320 C. and holding it there until 
 the oil has reached the proper viscosity and gravity. 
 This process which, instead of utilizing the oil itself as 
 fuel, makes use of the cheaper heating mediums such as 
 
PROPERTIES OF INK-MAKING MATERIALS 95 
 
 gas, coal or electricity and shows a very small loss in the 
 oil. The maximum loss for medium oil being 2 per cent 
 and for strong oil 5 per cent, thus making production 
 of plate oils a great deal cheaper. Moreover the oils 
 made in this way are transparent, of much better color 
 and lack the disagreeable empyreumatic odor of the 
 burnt oils; they are also entirely free from carbon and 
 contain a much lower percentage of free fatty acids. 
 
 It has continually been contended that the oils made 
 in this way were not suitable for plate inks but the 
 authors have proved that this is not the case. Plate 
 oils made by this process have been used by us prac- 
 tically and on a large scale and the ink made from them 
 has shown superior working qualities to the inks made 
 from the old process burnt oils. 
 
 The apparatus shown in figure 5 was designed by the 
 authors with a view to preventing the oils from acci- 
 dently boiling over, to keep the loss to a minimum and 
 to carry away the obnoxious fumes arising in the process. 
 Electrical heat was employed on account of its economy, 
 the niceness of control possible with it and because it 
 obviates the danger of fire. 
 
 SOYA BEAN OIL 
 
 The only oil that, at present, in any way compares with 
 linseed oil as a drying oil for use in printing inks, is 
 soya bean oil. This oil dries a little slower than linseed 
 oil and when dried exhibits a film not quite so hard and 
 durable but more elastic than that from linseed oil. 
 The authors found that inks made from soya bean oils 
 and varnishes were almost similar in working qualities 
 and appearance to those made with similar linseed oil 
 
96 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 vehicles but were just a trifle softer and more greasy. 
 These inks, which were made with drier, dried about as 
 well as linseed oil inks. Soya bean plate oils and typo- 
 graphical varnishes can be used as substitutes for linseed 
 
 FIGURE 5. APPARATUS FOR MAKING PRINTING INK VARNISHES. 
 
 oil varnishes, except for the highest grade of work. In 
 making printing ink oils and varnishes from soya bean 
 oil, the same processes are used as are employed for 
 making linseed oil plate oils and varnishes. 
 
PROPERTIES OF INK-MAKING MATERIALS 97 
 
 Soya bean oil is pressed from the soya bean, originally 
 a native of China and Manchuria but now grown through- 
 out the world for fodder. In this country it is widely 
 grown for feeding purposes but as yet no attempts have 
 been made to crush the beans for oil. Its constants are 
 somewhat lower than those of linseed oil and samples 
 from different sources show great variations. Up to the 
 present time there has been very little published about 
 soya bean oil, as its introduction as a competitor to lin- 
 seed oil has occurred within the last few years. 
 
 Samples analyzed by the authors gave the following 
 range of constants: 
 
 Specific Gravity 9240 to .9270 
 
 Acid Value 70 to 5.2 
 
 Iodine Value 124.5 to 148.6 
 
 Saponification Number 192.8 to 194 
 
 ROSIN OIL 
 
 Rosin oil and rosin oil varnishes are very important 
 ink-making vehicles, there use, however, being restricted 
 to the typographic inks. They are generally used as 
 substitutes for linseed oil varnishes for the cheaper 
 grades of ink, but are sometines used with linseed var- 
 nishes in high grade inks to impart some special property 
 or to meet some special condition of work. 
 
 Rosin oil, of itself, is a non-drying oil, drying when 
 used in inks only by absorption into the paper but when 
 boiled with certain driers it forms an oil that dries 
 fairly well. In combination with rosin it makes a good 
 substitute for gum varnishes. 
 
 Rosin oil is obtained by subjecting colophony to de- 
 structive distillation and is separated by fractionation 
 
98 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 into four different runs of different consistency and 
 gravity. The first run is the lightest while the fourth 
 run is a heavy, thick, tacky oil of about the same con- 
 sistency as strong linseed plate oil or No. 4 lithographic 
 varnish. 
 
 PARAFFINE OIL 
 
 Paraffine oil is a distillate from the residues of crude 
 petroleum with a specific gravity of from .800 to .820. 
 It is largely used as a vehicle for cheap inks. It has no 
 drying properties whatever except by being absorbed 
 into the paper. Paraffine oil is also largely used in mak- 
 ing various special varnishes. 
 
 KEROSENE OIL 
 
 Kerosene oil, in connection with some long varnish, is 
 used as a vehicle for very cheap inks for use on news- 
 papers. 
 
 TYPOGRAPHIC VARNISHES 
 
 A. Linseed Oil Varnishes. The principal typo- 
 graphic varnishes are made from burnt or boiled linseed 
 oil and come on the market in a number of grades of 
 consistency that can be mixed into combinations to suit 
 the character of work for which the ink is to be used, 
 and the physical characteristics of the dry color em- 
 ployed. 
 
 The linseed oil varnishes range in consistency from a 
 thin varnish, a little heavier than raw linseed oil, and with 
 about the same drying properties as a painter's boiled 
 oil, to one so heavy that it will not flow till warmed and 
 which dries very rapidly. The heavy lithographic var- 
 nishes of linseed oil are very tacky. The varnishes are 
 
PROPERTIES OF INK-MAKING MATERIALS 99 
 
 sold by numbers according to their tack, viscosity, gravity 
 and drying qualities. The thin varnishes range from oooo 
 to o and the heavy ones from i to 8. These varnishes 
 are made in the same way as plate oils either by burning 
 or boiling the oil to the proper consistency, tack and 
 drying properties. In some cases for the more rapid 
 drying grades a drier is added such as borate of man- 
 ganese, red lead or a metallic soap of rosin, linseed oil 
 or tung oil. 
 
 A varnish of high gravity but of little viscosity can be 
 made by air-blowing linseed oil at 100 C.; this oil is 
 soft and buttery and has a soft body that makes the ink 
 stand up without being tacky. This together with the 
 fact that it is slow drying makes it an ideal vehicle for 
 offset inks. 
 
 It can readily be seen that it is possible by judicious 
 blending of these varnishes to produce inks of the right 
 degree of tack, softness and drying properties for any 
 purpose or process. 
 
 B. Gum Varnishes. Gum varnishes are made from 
 certain gum resins, most commonly damar and kauri. 
 These are melted and mixed with linseed oil heated to a 
 high temperature with or without the addition of driers; 
 this depending on whether a quick drying or moderate 
 drying varnish is desired. These varnishes give gloss 
 to the printed work and a heavy body and great tack 
 to the ink. Inks made with them stand up well on 
 the paper and dry extremely hard. Gum varnishes are 
 always used in combination with other varnishes. 
 
 C. Rosin Oil Varnishes. Rosin oil varnishes are 
 made by heating rosin oil up to 360 C. and adding 
 either borate of manganese, red lead or a metallic soap 
 
ioo CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 of rosin. These rosin oil varnishes can be used in 
 place of the linseed oil varnishes for the cheaper grades 
 of ink. 
 
 There is also a gum varnish substitute made by dis- 
 solving rosin in rosin oil which is known also as rosin oil 
 varnish. In very cheap work a varnish made from par- 
 affine oil and rosin can be used in place of rosin varnish. 
 When properly made this varnish gives good results and 
 is quite cheap. 
 
 D. Long Varnishes. There are certain varnishes 
 made from combinations of asphaltum, rosin, stearine 
 pitch, paraffine oil, wood tar and kerosene oil that are 
 known as long varnishes on account of their length and 
 tack. Different amounts and combinations of the above 
 materials give varnishes of different degrees of tack and 
 length. These varnishes are particularly valuable when 
 it is necessary to use a pigment which in itself is short. 
 Being dark in color they cannot be used except for black 
 or darkly colored inks. 
 
 REDUCERS AND MISCELLANEOUS MATERIALS 
 
 A. Asphaltum. The asphal turns are natural hydro- 
 carbons which occur in several forms, the principal differ- 
 ences being in their melting points. Asphaltum is a 
 brilliant, black material with a distinctly brown under 
 hue. As a rule it is hard at ordinary temperatures but 
 there are several varieties that are semi-liquid. Besides 
 being used for varnish making, it is also used to some 
 extent in the manufacture of duo-tone inks, where its 
 brown under hue is taken advantage of. 
 
 Asphaltum is also used in preparing lithographic plates 
 
PROPERTIES OF INK-MAKING MATERIALS 101 
 
 and in making transfer inks. It is readily soluble in all 
 the common solvents and is taken up easily when heated 
 with paraffine oil or kerosene. 
 
 B. Petrolatum. Petrolatum is useful for making an 
 ink run smoothly on the press, to correct fast drying in 
 inks that must have a heavy consistency, to take out 
 tack and to shorten inks that are too long. 
 
 C. Soap. Soap is also used to make inks work 
 smoothly, to shorten naturally long inks and to give better 
 distribution. 
 
 D. Lanolin. Lanolin or purified wool grease will also 
 answer the same purpose as soap but is a little more 
 sticky. 
 
 E. Miscellaneous Materials. Beeswax, spermaceti, 
 carnauba wax, paraffine wax, oil of lavender, venice tur- 
 pentine, balsam fir, balsam of copaiba, gum mastic, 
 stearic acid and olive oil are also used to some extent in 
 making specialities for imparting certain properties to 
 inks but they are mostly used in making different 
 kinds of transfer inks and preparations for lithographic 
 work. 
 
 F. Reducers. For reducers to make stiff inks thin, 
 particularly lithographic and offset inks, and to keep 
 inks from drying too fast the following materials are 
 generally used: 
 
 The very thin grades of linseed oil varnish. 
 
 Rosin oil (particularly to correct fast drying). 
 
 Paraffine oil. 
 
 Kerosene oil. 
 
 Amyl acetate. 
 
 Ether. 
 
 Oleic acid. : ; > ' ' >' 
 
102 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 The last three are particularly used in offset work; they 
 should however be used sparingly. 
 
 Ether and amyl acetate are used because they are 
 volatile, the theory being that they thin the ink in the 
 fountain but volatilize by the time they reach the work, 
 thus giving an impression that consists mostly of pig- 
 ment and therefore has more color. That these materials 
 really accomplish this effect is extremely doubtful. 
 
 Oleic acid is supposed to assist in preserving the work 
 on the plate. It is used in very small quantities, a few 
 drops to a fountain full of ink. 
 
 DRIERS 
 
 The principal driers used in printing inks are the 
 straight metallic driers, such as borate of manganese and 
 red lead, the metallic soap driers which consist of the 
 resinates, linolates and tungates of lead and manganese 
 dissolved in linseed oil, and the japan driers, which 
 consist of a varnish gum and one of the metallic soap 
 driers dissolved in linseed oil and thinned with turpentine. 
 
 The first class of driers are used principally in plate 
 inks and they are generally worked into a paste with 
 linseed oil and paris white. 
 
 The resinates, linolates and tungates can be made in 
 two ways either by saponifying the rosin or oils, pre- 
 cipitating the acids with sulphuric acid and saturating 
 the free acids with lead or manganese carbonate or by 
 precipitating the soap solution directly with a solution 
 of lead nitrate or manganese sulphate. The soap driers 
 and japan driers are generally used exclusively in typo- 
 graphic. /work. 
 
PROPERTIES OF INK-MAKING MATERIALS 103 
 
 There are a number of patented and special driers on 
 the market but it is unnecessary to mention them here 
 as they are merely modifications in some way of the 
 three classes of driers mentioned above and any work 
 claimed for them can be done by the above mentioned 
 driers just as well. 
 
PART THREE 
 
 SECTION ONE. THE MANUFACTURE OF 
 PRINTING INK 
 
 GENERAL CONSIDERATIONS 
 
 IN the manufacture of printing ink there are four gen- 
 eral essentials for producing good inks. 
 
 First, the material should be properly proportioned, 
 that is, the pigments should be carefully weighed out so 
 as to make the color desired directly, without additions, 
 and this can generally.be done if a formula is worked up 
 in a small way in a laboratory. The vehicles should 
 always be carefully weighed with the error on the side 
 of stiffness rather than softness, as it is easier to make a 
 stiff ink soft than to stiffen up a soft ink, as the latter 
 requires the addition of dry pigment and this is very 
 troublesome, especially if the color is a mixture of two or 
 more pigments. In this case there will always be some 
 difficulty in matching the color. It might be noted that 
 many colors which seem stiff when mixed will be a great 
 deal softer after running through the mills. In these 
 cases experience must be the teacher. 
 
 Secondly, the materials must be thoroughly mixed, every 
 particle of pigment be brought into contact with the 
 varnish and the whole mass wet out so that it has a 
 uniform consistency. 
 
MANUFACTURE OF PRINTING INK 105 
 
 Thirdly, the ink should be sufficiently ground to get 
 the necessary homogeneity and smoothness. AS will be 
 stated later, some inks from the nature of the pigment 
 used and the kind of work the ink is going to be used 
 on, require more grinding than others. Typographic 
 inks, especially, should be ground to a great degree of 
 fineness and smoothness. In using roller mills, care 
 should always be taken to cut off the ink that runs to 
 the edges and return it to the hopper to be reground. 
 
 Fourthly, all inks, after coming from the mills should 
 be blended; that is remixed, so that the color will be 
 uniform. This is particularly necessary in inks that are 
 made from two or more pigments and for pigments that 
 have any tendency to work away from the oil. Correc- 
 tions in the hue or consistency of the inks should be made 
 at the time of blending. For the purpose of correcting 
 the hue a set of stock inks consisting of the various pig- 
 ments ground in oil or varnish should be kept on hand. 
 The addition of these will bring the ink to the proper 
 hue and consistency at the same time and obviate the 
 necessity of regrinding the batch, which would be neces- 
 sary if dry pigments were added. In correcting the hue 
 of inks it should be remembered that not only the top 
 hue but also the under hue should be matched. This 
 is more important in plate printing and halftone work 
 than it is in general typographic work. The main thing 
 to be considered in ordinary typographic work is top hue. 
 
 The weighing of the pigments, oils and varnishes can 
 be done on regular platform scales, the pigments being 
 weighed into rectangular sheetiron boxes fitted with 
 handles for lifting. In the case of carbon black, which is 
 so light as to make it difficult to handle, we make the 
 
io6 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 mixing of such a size that the material can be dumped 
 directly into the mixer out of the original bag it was 
 received in without extra weighing. 
 
 The oils and varnishes should be stored in tanks fitted 
 with spigots and these materials run directly from the 
 
 FIGURE 6. MIXER FOR MAKING LARGE BATCHES or INK. 
 
 tanks into tared receptacles on the scales. These 
 receptacles should be of such a design as to allow the 
 vehicle to be entirely emptied into the mixer without loss. 
 For inks to be mixed in a pony mixer, the oils or var- 
 nishes should be weighed directly into the mixer cans and 
 
MANUFACTURE OF PRINTING INK 
 
 107 
 
 the pigments added when the can is on the mixer. Care 
 should be taken that all cans and boxes should be 
 thoroughly cleaned before using. The mixing should be 
 done on one of two 
 regular types of mixers. 
 For large batches and 
 for stock colors, which 
 are regularly made in 
 large amounts, a mixer 
 of the bread or dough 
 mixer type shown in 
 Figure 6 should be used. 
 These mixers should be 
 provided with a close 
 fitting cover and a de- 
 vice for dumping. The 
 authors have found that 
 a mixer of this pattern 
 with gears on both sides, 
 driven by an individual 
 motor with a noiseless 
 chain drive are most 
 
 FIGURE 7. PONY MIXER. 
 
 satisfactory. For small batches of ink and odd colors 
 not regularly made, where frequent and thorough clean- 
 ing is necessary, the type of pony mixer shown in Fig- 
 ure 7 is desirable. This type of mixer is also especially 
 adapted to blending batches of ink which need correction 
 for hue. 
 
 The three-roll, water cooled, paint mill is the best mill 
 for grinding inks. This mill, as shown in Figure 8, con- 
 sists of three hollow rolls of hard steely two of which, the 
 outside ones, revolve in the same direction but opposite 
 
108 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 from the middle one; these rolls are water cooled to 
 prevent the friction heat from affecting the ink and are 
 
 FIGURE 8. MODERN THREE ROLL, WATER COOLED INK MILL, 
 SHOWING AUTOMATIC FEEDING ARRANGEMEMT. 
 
 adjustable so that different amounts of pressure can be 
 obtained. The ink is fed into the back and middle rolls 
 
MANUFACTURE OF PRINTING INK 
 
 109 
 
 between two movable hoppers and is cut off from the 
 front roll by a steel knife onto a sloping apron. The 
 knife edge should be kept sharp and should always bear 
 
 FIGURE 9. STONE MILL FOR GRINDING INK WHERE A GREAT DEGREE 
 OF FINENESS is NOT REQUIRED. 
 
 true against the roll throughout its whole length. The 
 rolls are geared so that they revolve at different speeds. 
 The most satisfactory way of running the mills is with 
 individual motors and noiseless chain drives. 
 
 For grinding large quantities of plate inks to be used 
 
no CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 on a power press where a great degree of fineness is not 
 necessary, a stone mill as given in Figure 9 is satisfactory. 
 
 EXPLANATION or TERMS 
 
 The following definitions of terms used in the printing 
 trade to explain certain conditions arising in the work 
 will serve to explain what is meant when these terms 
 are used in the following pages. 
 
 Striking Through. When an ink is very thin or made 
 from a pigment that is soluble in oil, the oil will penetrate 
 through the paper, showing up on the back of the printed 
 sheet either a greasy mark or a discoloration. This is 
 due to the penetration of the oil before it has time to dry, 
 to the fine particles of the pigment being carried into 
 the paper by the oil and to the solubility of the pig- 
 ment itself in the vehicle. This defect is called striking 
 through. 
 
 When work is printed wet, as is often the case in plate 
 printing, this striking through is sometimes due to pig- 
 ments somewhat soluble in water. 
 
 Bleeding is defined in a former chapter as the solu- 
 bility of a pigment in a vehicle or in water, therefore 
 when striking through is due to either of these causes it 
 can be said to be caused by bleeding. 
 
 Offsetting. When the ink from one sheet comes off 
 on the back of the sheet that is laid on top of it, the ink 
 is said to offset. There is a method of printing called 
 offset printing that will be spoken of later on. 
 
 Permanency. This means the resistance of an ink to 
 light, almospheric and chemical influences. 
 
 Picking Up. When the ink on the plate or form pulls 
 out little fibers from the paper it is said to pick up. 
 
MANUFACTURE OF PRINTING INK III 
 
 Gathering and Graining. In plate printing, when an 
 ink collects in little hard or stringy lumps on the roller or 
 ink slab it is said to gather. When the same effect appears 
 on the rollers of a typographic press it is called graining. 
 
 Wiping. The wiping of an ink in plate printing is 
 the way it acts when wiped off the plate by the printer's 
 cloth. After inking in his plate, the printer takes a 
 starched cloth and wipes the superfluous ink off. The 
 ink should come off clean with the cloth but should not 
 come out of the lines. 
 
 Polishing. This is the way the ink leaves the plate 
 when the plate is polished by the printer's hand. After 
 wiping, there is generally a thin film of ink left on the 
 plate, and the printer polishes the plate with his hand to 
 clean this scum off. After polishing, the plate should be 
 perfectly clean without any film of ink on it. 
 
 Tints. In reference to color, the meaning of a tint 
 has been explained in a former chapter as a color lightened 
 with white. In printing terms it is used in a somewhat 
 different meaning, namely to denote an ink printed very 
 faintly and lightly on paper. 
 
 Tinting. When for any reason the ink is taken up 
 on the low parts of a form or when a plate ink has not 
 been polished clean off the plate and this causes a slight 
 discoloration of the whole impression it is said to be 
 tinting. This can be caused by a number of things, 
 chiefly, however, by the lint from the paper filling up the 
 forms, and by the use of a gummy ink with a good deal 
 of light varnish in it, which spreads over the entire plate 
 when the press speeds up. 
 
 In the case of plate inks, this is due to a hard wiping 
 or greasy ink. 
 
112 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 Rubbing Off. When a printed sheet is handled after 
 sufficient drying and the ink smears or comes off on the 
 hand, it is said to rub off. 
 
 Greasy. A greasy ink is one that leaves a scum over 
 the plate or form or leaves a greasy margin around the 
 printed work. 
 
 Greasiness is due to the use of too thin a vehicle, too 
 thin an ink or to the use of a vehicle that does not dry 
 rapidly enough or to a combination of all three of these 
 defects. 
 
 Duo-Tone Inks. Duo-tone inks are those that show 
 a black over hue and a decided brown under hue, giving 
 the impression that the print has been made with two 
 printings, using different inks. 
 
 PRINTING INKS 
 
 Printing inks are divided into two general classes 
 according to the two basic processes of printing. These 
 two basic processes are plate printing, done on intaglio 
 plates, and typographic printing, done either from surface 
 plates such as lithographic plates, or raised plates, or 
 types such as electrotypes and lead types, where the ink- 
 taking surface is raised above the body of the plate. 
 Of course there are many modifications of these two 
 processes in actual use and the ink necessary for these 
 modifications varies with the variations in the process. 
 Therefore under the head of plate printing inks and typo- 
 graphic inks as broad classes will be comprised the 
 various inks suitable for the different modifications of 
 these two general processes. 
 
 1. Plate Printing Inks. Hand-press inks should 
 have a certain amount of length to make them stand up 
 
MANUFACTURE OF PRINTING INK 113 
 
 and hold in the lines when wiped. This length is pro- 
 duced by the use of strong oil. Too much length, how- 
 ever, results in a stringy, hard-wiping ink. This can be 
 remedied by reducing the amount of strong oil or in 
 cases where reducing the strong oil will result in a soft 
 ink the base can be increased or a little aluminum hy- 
 drate added. Aluminum hydrate will also improve the 
 polishing of an ink when it has a tendency to cause 
 tinting. 
 
 Where the ink is too soft and has a tendency to mash 
 out of the lines the strong oil should be increased and the 
 medium oil decreased. 
 
 If an ink dries too quickly the drier is cut down. In 
 some cases the addition of medium oil, if this does not 
 make too soft an ink, will also help. 
 
 Gathering is generally due to coarse, dry colors and can 
 be corrected by the use of finer raw materials and 
 thorough mixing. In some special cases, the addition of 
 other material will stop gathering. These special cases 
 will be noted under the head of the color when they 
 occur. 
 
 Inks that do not fill in well are too stiff and should be 
 softened by the addition of medium oil. 
 
 Power-press inks should be made as thin as it is pos- 
 sible to make them without having them mash or pull 
 out of the lines. They only require length enough to 
 make them feed well on the roll and for this reason 
 medium and weak oils are used instead of medium and 
 strong oil, as is the case in hand-press inks. When 
 power-press ink pulls out of the lines when it is wiped, 
 it is generally too short; a little strong oil can be added 
 to correct this. Sometimes this wiping out is due to 
 
114 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 too dry an ink and it can be remedied by adding medium 
 oil. When an ink does not fill into the plate well and, 
 therefore, prints out light, it can be made to fill in and 
 print better by the addition of medium or weak oil. 
 When an ink feeds badly or lacks distribution a little 
 strong oil can be added to it. If the ink has a tendency 
 to mash it should be stiffened by dropping some of the 
 oH. 
 
 For all plate inks the materials having the lowest oil 
 absorptions are the best. When the oil absorption of a 
 color is very great it is of no value as a plate-ink pig- 
 ment. A pigment of moderately high oil absorption can 
 be mixed with one of lower oil absorption or the oil 
 absorption can be reduced by the addition of more base. 
 
 A certain amount of base is necessary in all plate inks 
 except blacks, to give the ink grain and body, to hold it 
 in the lines, to make the impression sharp and clear, to 
 make it wipe well without being too short and to improve 
 the polishing. Without base the ink would fill in badly, 
 pull out of the lines, wipe hard, be sticky and tacky, 
 and tint the plate, making it hard to polish and impos- 
 sible to get a clear impression. 
 
 The tinting of plate inks should be done with zinc white 
 as white lead is heavy, has a tendency to separate on 
 standing and chalks after being printed out. It also 
 works greasy. 
 
 In correcting apparent faults of inks, the condition of 
 the starched cloths should be carefully examined as too 
 soft or too stiff a cloth will cause a great deal of differ- 
 ence in the working of an ink, particularly on a power 
 press. The paper also has some influence on the behavior 
 of the ink; a paper that is too wet or not wet uniformly 
 
MANUFACTURE OF PRINTING INK 115 
 
 causing a good deal of trouble due to the ink not taking 
 hold of the paper and therefore giving a light impression. 
 Where the water is on the paper in spots or drops the ink 
 at that particular place does not print and the lines will 
 be broken; this is what is known as a waterbreak. 
 
 A. Black Plate Inks. The highest grade of black 
 plate inks are made from pure, acid washed bone black, 
 finely ground, and brought to the proper color by the 
 addition of a high-grade vine black, and enough prus- 
 sian blue to fully develop the black, but not enough to 
 blue the under hue. 
 
 For hand-press ink these materials are mixed to the 
 proper consistency with strong and medium oil; about 
 six times as much medium oil as strong oil being used, 
 and about two pounds of borate of manganese added to 
 every 100 pounds of oil. In mixing the black, the oil 
 and drier should be put into the mixer first and the blacks 
 and blues added a little at a time until it is thoroughly 
 mixed. The mixture should then be ground on a three- 
 roll mill once or twice, according to smoothness. 
 
 If the ink shows a tendency to wipe hard the strong 
 oil should be reduced. Too much drying and stiffness 
 can be corrected by adding medium oil. If the ink is too 
 thin and has a tendency to mash add more strong oil. 
 If the addition of medium oil does not correct the drying 
 or makes the ink too thin cut down the drier. 
 
 Gathering can be lessened by increasing the medium 
 oil and having the materials ground finer. Coarseness 
 of raw materials is a very prolific cause of gathering. If 
 these two remedies fail to have the desired effect a small 
 amount of magnetic pigment described under special 
 blacks will be found to improve this condition. 
 
Il6 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 Sometimes blacks have a tendency to puff up on the 
 mill and to become spongy; this is due to occluded air 
 in the black and it generally takes place in air-separated 
 blacks. There is nothing that can be done to remedy 
 this condition except to take care that the air is entirely 
 gotten out of the black in packing. 
 
 All the materials that go to make up blacks should be 
 low in oil absorption. The black pigments used should 
 not require more than 65 parts of medium oil to 100 
 parts of color. 
 
 In making black ink for use on power presses, the 
 strong oil should be left out entirely and its place taken 
 by about half as much weak oil as there is medium oil. 
 The borate of manganese should also be increased about 
 \ pound for every 100 pounds of oil. The above formula 
 will give a very satisfactory black plate ink, the cost and 
 grade depending on the kind and value of the bone and 
 vine blacks used. 
 
 Plate inks made from carbon or lampblack will not 
 work satisfactorily as they lack grain and body and have 
 a very high oil absorption. 
 
 B. Green Plate Inks. Fine green plate inks, made 
 from chrome green should be lightened with chrome 
 yellow lemon. Chrome green being very dark in itself, it 
 is never necessary to shade it. For cheaper work the 
 green can be lightened with barytes but this produces a 
 pale tint with blue hue that is liable to chalk. When 
 yellow is used to lighten green it gives a green of light 
 top hue and slightly yellow under hue. If a very light 
 green tint is required zinc white can be used with yellow 
 as a diluting agent. In order to make a green plate ink, 
 made with chrome green and chrome yellow lemon work 
 
MANUFACTURE OF PRINTING INK 117 
 
 satisfactorily, it is necessary to use a base; this should 
 be a water-floated barytes with about 10 per cent of 
 paris white in it. A good chrome green ink will stand 
 about 50 per cent of this base. The base makes the ink 
 wipe and polish well and keeps it from rubbing off. 
 Chrome green plate inks dry well naturally and in most 
 cases it is unnecessary to add drier. 
 
 The green used for hand presses should have about 
 ij pounds of strong oil to every 100 pounds of medium 
 oil to prevent it from flowing out on the stone. While 
 green plate inks are always used softer than black inks, 
 care should be taken not to get the consistency too thin 
 as this will cause mashing. If the green wipes badly the 
 strong oil should be decreased or the base increased a 
 little. A slight increase of base also corrects tinting, a 
 fault inherent in all greens. When the green ink gathers 
 the medium oil is increased. 
 
 In mixing greens, the green, yellow and part of the 
 medium oil should be mixed and ground first, being put 
 through the mill once. Then the base, the strong oil and 
 the rest of the medium oil is added to the mixture and 
 the whole mixed thoroughly and reground. For power- 
 press inks the strong oil is left out and enough weak 
 oil to bring the ink to the proper consistency is used. 
 
 Up to the present time there are no very satisfactory 
 green lakes on the market for use in plate inks. 
 
 Olive green can be made by mixing prussian blue with 
 the medium hue of chrome yellow. This gives a bright 
 olive; it can be shaded with a little vine black or light- 
 ened with a little chrome yellow lemon. Its base should 
 be barytes. Olive inks should be ground about three 
 times to prevent the separation of the blue on standing. 
 
n8 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 C. Yellow Plate Inks. The chrome yellows give 
 very satisfactory working plate inks but when a fine 
 permanent ink is desired one of the permanent yellow 
 lakes will be found not only to work better but also to 
 be more permanent and brighter than the chrome colors. 
 The chrome yellows will carry about 50 per cent of base 
 while the yellow lakes will carry slightly more, being 
 stronger and brighter. The question of price and the 
 class of work figures largely in the choice between the 
 chrome yellows and the yellow lakes. 
 
 D. Blue Plate Inks. The blue mineral pigments 
 all make good working inks of fairly low oil absorption, 
 except ultramarine blue which works up into a tacky, 
 hard-working ink. There are, however, very permanent 
 blue lakes without these faults that will match ultra- 
 marine blue in color. There are a number of blue lakes 
 of all hues on the market that surpass in working quality 
 and permanency all of the mineral blues, but they are 
 quite expensive as compared with the mineral blues. 
 A small amount of drier should be added to all the 
 blues. 
 
 E. Red Plate Inks. Among the red inks there are 
 no satisfactory ones made from mineral pigments. Ver- 
 million and orange mineral, the latter not being really 
 a red but an orange, make very poor working inks. Ver- 
 million is a very heavy pigment and settles out from the 
 ink and on this account causes the ink to gather a great 
 deal and to fill in poorly, defects that it is impossible to 
 remedy. Where vermillion must be used it should always 
 be used with some similar hued pigment. Vermillion 
 inks always require driers. 
 
 Orange mineral ink has the same defects as the ver- 
 
MANUFACTURE OF PRINTING INK 119 
 
 million ink with the added disadvantage that this pig- 
 ment exerts a great drying action on the oil, causing the 
 ink to harden up rapidly. It also has a tendency to 
 form a soap with the oil, which results in a livery mass 
 that cannot be worked. Of the two grades of orange 
 mineral, French and German, the French orange mineral 
 is the better. 
 
 Since there are a number of absolutely light and at- 
 mospherically fast aniline lakes of all hues of red, from a 
 brilliant scarlet to an orange of red hue, which possess 
 perfect working qualities, it is an easy matter to match 
 the color of any red. The red lakes will carry a great 
 deal of base when made into ink. The most common 
 fault of the red lakes is shortness and care should be 
 taken to avoid those colors that have a high oil ab- 
 sorption or show shortness. The addition of a little 
 more base will make an ink of this character work 
 better, if it is necessary to use a pigment that is short. 
 All red lake inks should be made up with a drier. 
 
 F. Degraded Colors. In making degraded colors 
 the pigments to be mixed must be selected with a view 
 to avoiding colors that will act on each other chemically. 
 They should also be selected with reference to their 
 specific gravity and oil absorption. Colors that are 
 close to each other in specific gravity should always be 
 selected, as this will prevent the separation of the two 
 colors on standing. When pigments of widely different 
 specific gravity are used, this separation will take place 
 no matter how intimately the ink is mixed or how often 
 it is ground. Two colors of relatively high oil absorp- 
 tion should not be used together but an attempt made to 
 secure an average oil absorption where it is necessary 
 
120 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 to use a pigment that takes a great deal of oil by com- 
 bining it with one that takes very little. 
 
 In mixing inks of degraded colors a set of stock colors, 
 consisting of the different materials needed in the mix- 
 tures and ground in medium oil, should be kept on hand 
 and the final adjustment of top hue and under hue made 
 by adding from these stock inks. Care should be taken 
 in making this final adjustment that the under hue is 
 not changed too much in attempting to bring up the top 
 hue and vice versa. 
 
 In plate printing, both the under hue and top hue must 
 be taken into consideration as they are both brought out 
 in this work and it is necessary to match a sample in 
 both these particulars. The fewer pigments used to 
 obtain a color effect the better the ink will be and the 
 easier it will be to match at some future time. 
 
 In matching or comparing samples printed at two dif- 
 ferent times, allowance must be made for the time the 
 original sheet has been printed, as ageing and drying out 
 will affect all inks to some extent, especially the under 
 hue. The condition of the plate also has an effect on 
 the color and work done when a plate is new will always 
 look much brighter and stronger than that done on a 
 worn one. 
 
 2. Typographic Inks. Typographic inks are divided 
 into a great number of special classes, according to the 
 effects to be produced, different processes for producing 
 these effects and different styles of presses. Even inks to 
 be used to accomplish the same general effect have often 
 to be made slightly different from each other on account 
 of variations in the methods of use or in the kind and 
 quality of paper employed. 
 
MANUFACTURE OF PRINTING INK 121 
 
 Basicly typographic inks consist of a pigment and a 
 vehicle, all other ingredients being added to produce 
 some effect or remedy some defect due to the conditions 
 of the process to be employed or the style of press; as 
 for instance to increase or decrease the drying, to give 
 a gloss; to increase or decrease the body; to give length 
 or shortness. In all inks, especially typographic inks, 
 complicated formulas should be avoided and the materials 
 and effects desired so studied that a certain result is 
 reached with the simplest possible mixture of color and 
 vehicle. 
 
 A. Pigments. The best pigments for use in typo- 
 graphic work are the light and atmospherically fast organic 
 lakes, made on aluminum hydrate and blanc fixe; and 
 as these can be obtained in a number of different hues 
 and colors it is seldom that two of them have to be 
 mixed to produce a certain color. This is of great im- 
 portance, as frequently the mixture of two or more colors 
 of different gravity, oil absorption or working qualities 
 will result in a separation taking place in the fountain, 
 which will cause trouble in the feeding and distribution 
 of the ink. This is particularly true of the mineral pig- 
 ments which should never be used in typographic inks 
 except for the cheaper grades. The mineral colors are as 
 a rule satisfactory for plate printing inks as there is not 
 the demand in that sort of printing for the working quali- 
 ties, the very brilliant colors and the variety of hues 
 that are called for in lithographic and typographic 
 inks. 
 
 In typographic printing there is a demand for brilliant 
 colors of almost every hue, many of which must be 
 transparent and the only way that inks meeting these 
 
122 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 conditions can be produced is by the use of organic lakes, 
 principally those made from aniline dyes. In cases where 
 the ink manufacturer makes his own lake colors, the 
 best procedure and one that gives the most brilliancy is 
 to grind the lake directly into varnish as it comes from 
 the filter press without any drying, as drying always 
 has a tendency to dull the color and in some cases even 
 changes the hue of the lake. Where a lake color is to be 
 dried before use, the latest factory practice is vacuum 
 drying which does not affect the color nearly as much 
 as drying by heat alone and which does not require 
 nearly as much care and attention to produce a uni- 
 form product. In grinding moist lakes into ink, the 
 lake should first be ground in a small amount of heavy 
 varnish until all the water has separated out and then 
 ground with the other varnishes to the consistency 
 desired. 
 
 For producing tints in typographic inks, zinc white 
 should be used while for making transparent ink, alumi- 
 num hydrate is the proper material. In making a tint 
 in typographic work a very thin ink with just enough 
 tack to make it take on the rollers and distribute, is most 
 satisfactory and in many cases tint inks are dyes dis- 
 solved in the vehicle. 
 
 B. Vehicles. The use of the different vehicles is 
 dependent on the class and cost of the ink desired. In 
 general, for all high-grade inks, linseed oil varnishes of 
 different consistencies are used as the basic vehicle. In 
 cheaper inks rosin oil is used, while in very common inks 
 such as newspaper and handbill inks, petroleum oils into 
 which some paraffine wax has been ground, are used. 
 
 There are a number of grades of linseed oil varnishes 
 
MANUFACTURE OF PRINTING INK 123 
 
 of different consistencies as noted in the preceding chap- 
 ter on oils and varnishes. These run in consistency from 
 an oil slightly heavier than raw linseed oil up to a stiff 
 almost glue-like mass. Some of these varnishes can be 
 used alone but a typographic ink usually contains a 
 mixture of two or more of these grades of linseed oil 
 varnish and some other varnish such as a gum varnish, 
 japan drier, asphaltum or some special product, added to 
 give a property not possessed by linseed oil alone. The 
 simpler, however, this mixture of varnishes is made the 
 better will be the resulting ink and the more pronounced 
 will be the effect desired. 
 
 Rosin oil comes in several different consistencies which 
 are used in the same way as linseed oil varnishes, but 
 for a different grade of work. Rosin oil is also used to 
 correct a fast-drying ink made from linseed oil varnishes. 
 Rosin oil, even in the cheaper grades of ink, is generally 
 used with some linseed oil varnish, as when used alone 
 it does not dry of itself except by absorption into the 
 paper and dries only to a certain limited extent when 
 used with metallic driers. Thus, when made without 
 linseed oil or a metallic drier rosin-oil inks rub off some- 
 what, as the vehicle is absorbed and the pigment is left 
 on the surface without much of a binder. This is espe- 
 cially true when the printing is done on an absorbent 
 paper. The use of rosin-oil inks without driers is never- 
 theless quite common. 
 
 Linseed oil varnishes dry partially by oxidation, that 
 is besides being absorbed to a certain extent by the paper, 
 the varnish itself dries in a film around the pigment so 
 that it will not rub off. 
 
 Gum varnishes are used to give tack, body and gloss. 
 
124 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 They also tend to make the ink stand out on the paper 
 somewhat and when used with linseed oil varnishes they 
 produce an increased drying effect. The gum varnishes 
 are used with oil varnishes either alone or in combina- 
 tion, depending on the effect to be produced and the 
 pigment used in the ink. No general rule for the use of 
 the different kinds of gum varnishes can be laid down as 
 the effects produced by them vary somewhat with the 
 process, paper and style of press used. Experience in 
 producing certain effects with certain combinations is 
 the best guide for their use. In using gum varnishes, 
 however, as small an amount as possible to produce the 
 effect desired should be used. Rosin varnishes and rosin- 
 oil varnishes are used to give the same general effects 
 as gum varnishes for cheaper inks; and are also used 
 to correct the fault of drying in inks which must have a 
 rather heavy body. 
 
 C. Driers. Driers are used when it is necessary 
 to increase the drying of an ink without changing its 
 consistency, length or tack and to make extremely quick 
 drying inks. An ink that dries slowly and offsets can be 
 made to dry more rapidly by the addition of a gum var- 
 nish and to dry quickly by the addition of a drier. A 
 gum varnish exerts only a moderate drying action while 
 a drier will make an ink dry rapidly. The addition of 
 a gum varnish is apt to change the consistency or the 
 properties of an ink so that if a moderate drying action 
 is desired and the addition of a gum varnish will make 
 the ink too stiff or tacky a drier can be added and the 
 drying regulated either with rosin varnish or rosin oil. 
 As a general rule the addition of the so-called reducers 
 and specialties should be avoided; however, the use of 
 
MANUFACTURE OF PRINTING INK 125 
 
 soap and petrolatum is of great assistance in making inks 
 soft or to make them work smoothly and cover well when 
 made from an inferior color. 
 
 The class of varnishes called long varnishes are used 
 to give length and flowing qualities to inks. They are 
 generally made on an asphaltum or wood tar base. There 
 are a number of ingredients that go into long varnishes 
 which are used in cases where the ink demands greater 
 or less length, tack and body. The demand for these 
 properties determines to a great extent what the com- 
 position of the varnish will be. 
 
 It must be remembered in making all inks that fre- 
 quently, with the same raw materials, a formula success- 
 ful in one case will give slightly different results in 
 another, especially under different weather conditions. 
 This matter of weather condition is one that in the work- 
 ing of inks has not been given any very serious considera- 
 tion, but it is a thing that plays a very important 
 part in the proper manipulation of many typographic 
 inks. 
 
 D. Offset Inks. For offset work the inks should 
 be short and have fairly little tack; the best inks are 
 rather stiff, that is, they carry a great deal more pigment 
 in proportion to the vehicle than the ordinary typo- 
 graphic ink, and should be somewhat buttery in con- 
 sistency although they should not be too greasy as the 
 grease tends to form a tint on the plate. They should 
 also be quite slow drying, as an ink that dries even mod- 
 erately fast will make frequent washing of the plate 
 necessary and every time it is washed the life of the plate 
 is shortened. An ink that dries fast or that is sticky 
 also piles up on the plate and causes the lines to spread, 
 
126 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 which is also a serious defect. The ideal ink for the 
 offset press is one that has only a moderate drying 
 action, that has only enough tack in it to feed well and 
 distribute properly, and has such a body that the greater 
 part of the ink that goes on the paper consists of pigment, 
 having, however, enough vehicle to hold the color with- 
 out rubbing. As the amount of ink that goes on the 
 plate is quite small, it can easily be seen that to get a 
 properly colored print a great deal of pigment must be 
 carried in a relatively thin layer of ink. 
 
 If the ink is too stiff it can be reduced with a weak 
 lithographic varnish, boiled linseed oil without driers or 
 with thin blown oil. Sometimes it is necessary to use 
 petrolatum or paraffine oil, but only small amounts of 
 either of these should be used as they have a tendency 
 to spread the work on the plate and to make the print- 
 ing strike through. In cases where the ink is too stiff 
 and tacky, petrolatum, mutton tallow or lanolin can be 
 used in small quantities with good effect. Ether and 
 banana oil are both recommended to make the ink dis- 
 tribute well and give greater color, but our experience 
 has been that an ordinarily soft ink made from proper 
 pigments, reduced when necessary with petrolatum or 
 paraffine oil, will accomplish more than these volatile 
 solvents which for the most part are dissipated before 
 the ink leaves the fountain and which are not healthy 
 additions to the heavy air of the average unventilated 
 press room. 
 
 We have found that the best basic vehicle for offset 
 inks is linseed oil, thickened to about the consistency of 
 No. i plate oil by blowing air through it at a tempera- 
 ture of about 100 C. 
 
MANUFACTURE OF PRINTING INK 127 
 
 A first-class grade of carbon black should always be 
 used for blacks and lakes precipitated on very soft- 
 grained aluminum hydrate should be used for colors. 
 An ink that separates out color or pigment to the very 
 slightest extent should be avoided as the slightest piling 
 on the plate makes a very bad looking job. The lati- 
 tude allowed on flat-bed or rotary cylinder presses using 
 electrotypes cannot be allowed in an ink for offset work. 
 
 For tints in offset work and in fact for any colored 
 work except black, a base consisting of equal parts of 
 magnesium carbonate ground in a thin varnish to a stiff 
 paste and a mixture of zinc white and aluminum hydrate 
 also ground in varnish will be found not only a good 
 reducer but also to give the necessary body and working 
 qualities to the ink. 
 
 SECTION TWO. DEFECTS OF INKS AND 
 THEIR REMEDIES 
 
 The usual difficulties met with in using typographic 
 inks and their remedies are as follows: 
 Working away from the ink rollers. 
 Lack of distribution. 
 Drying on the rollers. 
 Offsetting. 
 Flooding the type. 
 Picking up. 
 Filling the forms. 
 Tinting the forms. 
 Rubbing off after drying. 
 Graining on the roller. 
 Drying too fast. 
 Not drying fast enough. 
 
128 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 Working away from the Ink Rollers in the Fountain. 
 
 Frequently an ink will work away from the feed roller 
 in the fountain and the result will be that the plate or 
 forms do not get the proper amount of ink or the ink 
 that is fed, is not evenly distributed over the form or 
 plate and a poor print results. This is due primarily to 
 a short ink and this condition may be caused either by 
 the color mixing short or the use of too great an amount 
 of short varnish. The remedy for both these conditions 
 is to add a certain amount of varnish that has length. 
 In cases, however, where the pigment is in itself inherently 
 short in all varnishes, it is best if possible to use some 
 substitute of the same color and hue, that works properly. 
 Where the presence of a varnish contributes to this short- 
 ness it is best, besides adding a varnish that will give 
 length, to drop as much as possible of the varnishes that 
 are causing or contributing to the shortness of the ink, 
 where this can be done without affecting the results 
 desired in the finished work. This lack of distribution 
 or shortness is sometimes developed in an ink on stand- 
 ing but can be destroyed by restirring the ink. This is 
 probably due to some tension in the particles of pigment 
 and is most frequently encountered in certain grades of 
 carbon black. 
 
 Lack of Distribution. It is sometimes the case that 
 an ink will work well and feed from the fountain nicely 
 but will not distribute on the ink bed or rollers. Be- 
 sides being due to shortness this is sometimes due to a 
 soft ink and in these cases the tack should be increased 
 to such an extent that the ink will take hold of the rol- 
 lers easily and spread over all their surface. Sometimes, 
 however, this lack of distribution is caused by too rapid 
 
MANUFACTURE OF PRINTING INK 129 
 
 drying, the remedies for which are taken up in the next 
 paragraph. 
 
 Drying on the Rollers. Drying on the rollers is due 
 most often to an ink that dries too rapidly but sometimes 
 this is caused by an ink that is too tacky and for this 
 reason picks up and holds particles of lint or dust, and 
 it is not infrequently caused by conditions of the atmo- 
 sphere; so that an ink that works perfectly under the 
 ordinary conditions will dry rapidly in a spell of very 
 dry weather. It is best to decide first whether the drying 
 is the result of tackiness and if this is the case the rollers 
 and the ink on them will contain some fine particles of 
 lint and dust and not make a clean dried film but a 
 gummy mass, and the sheets are apt to show where the 
 paper has been picked up. If the trouble is from this 
 source the remedy lies in making the ink softer. If, how- 
 ever, the drying is due to a quick 'drying ink, that is, if 
 under any weather conditions the ink dries in a clear 
 film, the drier should be cut down or if there is no drier 
 in the ink and the drying is due to the influence of the 
 pigment used a small amount of non-drying oil should be 
 added. If the ink, which has been running well under 
 ordinary weather conditions suddenly begins to dry too 
 fast this condition can be remedied by adding a little 
 non-drying varnish to the ink in the fountain to meet 
 the change in the weather; inks that dry for this cause 
 should always be doctored in the fountain as this con- 
 dition may change at any time. 
 
 Offsetting. Offsetting may be due to a number of 
 things that must be taken up in order. It may be that 
 the ink is not getting its initial set fast enough, in which 
 case the amount of drier should be increased. It may 
 
130 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 be also due to lack of absorption of the paper, which 
 may have two causes: either the ink may be too stiff, in 
 which case it should be made thinner or it may be due 
 to a poorly made paper for which trouble there is no 
 way of improving the ink. Offsetting is also caused by 
 the printer allowing too much ink to go on the form and 
 this can be stopped by cutting down the feed of the 
 fountain. A sticky ink is also a cause of offsetting and 
 this can be stopped by adding petrolatum to the ink 
 and where gum varnishes are being used, by cutting down 
 the proportion of these varnishes. 
 
 Sometimes, especially in the case of high-speed web 
 presses and offset presses a little paraffine or beeswax 
 will remedy this defect. 
 
 Flooding the Type. Flooding the type or form is 
 caused by the printer opening his fountain too wide, the 
 use of too thin an ink or in the case of lithographic or 
 offset work the use of too little water or the absence of an 
 etching material in the water fountain. Where the work 
 in lithographic or offset printing does not come out clear, 
 it is well to add some etching solution to the water 
 fountain. 
 
 Picking Up. Picking up is caused either by too stiff 
 an ink, too tacky an ink or an ink that dries too fast 
 and, therefore, develops tackiness on the rollers, and also 
 by poor paper. When the ink is stiff it should be thinned 
 by the use of a weak varnish; when it is too tacky petro- 
 latum or a soft varnish should be added and if the ink 
 dries too fast the decreasing of the drier or the addition 
 of a non-drying varnish should help. Even when the 
 defect is caused by poor paper the trouble can be reme- 
 died to some extent by the use of the different materials 
 
MANUFACTURE OF PRINTING INK 131 
 
 described above. Of course this must be the subject of 
 experiment. 
 
 Filling the Forms. Filling up of the forms or type 
 may be due either to too rapid drying or the use of a 
 pigment that does not distribute well in the varnish. 
 This generally occurs when the ink is not ground well 
 enough to make it smooth, when the pigment itself is 
 coarse or when a pigment of heavy specific gravity is 
 used. Filling up is also caused by the accidental admix- 
 ture of some foreign matter such as lint from the paper, 
 dirt and dust from the air and the like. 
 
 Tinting the Form. When an ink has a pigment of 
 high gravity and a great deal of weak varnish in it or 
 when the ink is too thin bodied, the varnish will some- 
 times separate from the pigment, particularly when the 
 rollers become heated after a long, continuous run and 
 this varnish, faintly colored, will fill in between the lines 
 and leave a faint tint on the paper. To correct this fault, 
 which is most prevalent on high-speed presses, it is nec- 
 essary to give the ink more body. 
 
 Graining out on the Rollers. Tinting is generally 
 associated either with the filling up of the form or the 
 depositing of the pigment in a grainy condition on the 
 vibrating rollers. This graining out on the rollers is 
 caused by the separation of the pigment, due to the char- 
 acter of the pigment as explained under "filling the form" 
 or to the same cause as that of tinting, namely the use 
 of an excess of a thin-bodied varnish. The most satis- 
 factory remedy for all three of the above conditions is 
 to use a better working pigment or a heavier bodied var- 
 nish of little tack. 
 
 Rubbing Off. There are two varieties of rubbing off, 
 
132 CHEMISTRY AND TECHNOLOGY OF PRINTING INKS 
 
 one where the ink rubs off wet, and this can be remedied 
 by adding more drier, and another where the ink comes 
 off as a dust, due to the absorption of the vehicle into 
 the paper, leaving the pigment on top in a powdery form. 
 
 This can best be remedied by the use of a small amount 
 of vehicle that dries by oxidation or the addition of soap, 
 or some other material that will tend to keep the vehicle 
 from penetrating into the paper to such an extent that it 
 leaves the pigment no binder. 
 
 This kind of rubbing off is also caused by the particles 
 of coating, sizing or loading of the paper flaking off. 
 Some pigments have the tendency to dust inherent in 
 themselves. In these cases the pigment or paper should 
 be changed. 
 
INDEX 
 
INDEX 
 
 Abrasive qualities, definition of 9 
 
 Acid value, determination of in lin- 
 seed oil 23 
 
 Aluminum hydrate, manufacture 
 
 of 81 
 
 properties of 83-84 
 
 Amyl acetate 101-102 
 
 Analysis of, barytes 27-28 
 
 blacks 24-25 
 
 calcium sulphate 30 
 
 chromium colors S ^ 1 
 
 ferrocyanide blues 32-33 
 
 inks 2-4 
 
 linseed oil 22-26 
 
 lithopone 28 
 
 orange mineral 34 
 
 paris white 26-27 
 
 ultramarine blue 33 
 
 vermillion 31 
 
 white lead 29 
 
 zinc oxide 30 
 
 Aniline lakes 87 
 
 Asphaltum 100 
 
 Atmospheric influences, definition 
 
 of 12 
 
 Azo-colors, insoluble 86-87 
 
 B 
 
 Balances 19 
 
 Barium carbonate, determination 
 
 of in lithopone 29 
 
 Barium sulphate, determination of 
 
 in lithopone 28 
 
 Barytes, analysis of 28-29 
 
 manufacture of 79 
 
 properties of 83-84 
 
 Bases, properties of 78, 83, 84 
 
 Black plate inks 115 
 
 Blacks 63 
 
 analysis of 34~35 
 
 Blanc fixe, manufacture of 82 
 
 properties of 83-84 
 
 Bleeding, definition of 12 
 
 in oil, determination of 37 
 
 in printing inks no 
 
 in water, determination of 38 
 
 Blending inks 105 
 
 Blue plate inks 1 18 
 
 Break in linseed oil 91 
 
 determination of 25-26 
 
 Bronze blue, manufacture of 43 
 
 properties of 44~45 
 
 Body, definition of n 
 
 Body color, definition of n 
 
 Bone black, acid washed 64-65 
 
 manufacture of 64 
 
 properties of 72-73 
 
 sugar house 64-65 
 
 Burnt sienna, properties of 62-63 
 
 Burnt umber, properties of . .61, 62-63 
 
 Calcium, gravimetric determina- 
 tion of 26 
 
 carbonate, determination of 
 
 in paris white 26-27 
 
 sulphate, analysis of 30 
 
 Canary yellow 48-49 
 
 Carbon black 67 
 
 manufacture of 68 
 
 properties of 72~73 
 
 Carbon dioxide, determination of in 
 white lead 29 
 
136 
 
 INDEX 
 
 Chinese blue, manufacture of 42 
 
 properties of 44~45 
 
 Chrome green, manufacture of 53 
 
 properties of 54~55 
 
 Chrome yellow 45-46 
 
 manufacture of 46 
 
 properties of 50, 51, 52 
 
 Chrome yellow, lemon hue, manu- 
 facture of 48-49 
 
 properties of 50, 51, 52 
 
 Chrome yellow, orange hue, manu- 
 facture of 55-56 
 
 properties of 58, 59, 60 
 
 Chrome yellow, red hue, manufac- 
 ture of 56 
 
 properties of 58, 59, 60 
 
 Chromium, determination of in 
 
 chrome green 31 
 
 determination of in chrome 
 
 yellow 30 
 
 oxide, properties of 54-55 
 
 Citrines 62 
 
 Color strength, definition of 9 
 
 determination of 36 
 
 Damar gum 99 
 
 Defects of, plate inks and remedies 
 
 for 112-120 
 
 typographic inks and remedies 
 
 for 127-132 
 
 Degraded colors 119 
 
 Dilutents 74 
 
 Driers 102-124 
 
 Drop black 65 
 
 Drying, test of in linseed oil 23-26 
 
 Duotone printing inks 112 
 
 Ether... ..101-102 
 
 Fastness to light, definition of 12 
 
 method of testing for 18-19 
 
 Ferrocyanide blues, analysis of. . .32-33 
 
 Ferrocyanide blues, description of. . .41 
 
 Filtering apparatus 19 
 
 Fineness, definition of 9 
 
 determination of 37 
 
 Fire point, determination of in lin- 
 seed oil 23 
 
 Flash point, determination of in lin- 
 seed oil 23 
 
 Flow, definition of 10 
 
 Fluorides, test for in barytes 27 
 
 Foots and turbidity, determination 
 
 of in linseed oil 25 
 
 Forcing black 65 
 
 G 
 
 Gas black 67 
 
 manufacture of 68 
 
 properties of 72-73 
 
 Gathering of printing inks . . . in, 113, 
 
 115, 117-118 
 
 General classes of printing inks. ... 112 
 
 Graining of printing inks in, 131 
 
 Greasiness in printing inks. ... 112, 125 
 
 Green plate inks 116-117 
 
 Gum varnishes 99, 123, 124 
 
 H 
 
 Hanus solution 25 
 
 Hard black 65 
 
 Hue, definition of 7 
 
 Hydrometers 20 
 
 Incompatibility, definition of 12 
 
 Indian red, manufacture of 61 
 
 properties of 62-63 
 
 Iodine number, determination of in 
 
 linseed oil 25 
 
 Iron and aluminum, determination 
 
 of 27 
 
 J 
 
 Japan driers 102 
 
 K 
 
 Kauri gum 99 
 
 Kerosene oil 98 
 
INDEX 
 
 137 
 
 Laboratory apparatus 15-22 
 
 Lamp black, effect of in plate inks. .116 
 
 manufacture of 69 
 
 properties of 72-73 
 
 use in typographic inks 70 
 
 Lanolin 101 
 
 Lead, determination of in chro- 
 mium colors 30 
 
 determination of in white 
 
 lead 29 
 
 Length, definition of 10 
 
 Liebermann-Storch test 26 
 
 Light, ultraviolet 18-19 
 
 Lime, determination of in blacks 35 
 
 determination of gravimetri- 
 
 cally 26 
 
 Linseed oil 88 
 
 adulteration of 89-91 
 
 analysis of 22-26 
 
 blown 90-93, 99, 126 
 
 break in 25, 26, 91 
 
 constants of 90 
 
 treatment of 91-92 
 
 varnishes 98, 123 
 
 viscosity of 92 
 
 Linolate driers 102 
 
 Lithopone, analysis of 28 
 
 manufacture of 75~76 
 
 properties of 77~78 
 
 Livach's test 23 
 
 Livering, definition of 10 
 
 Long varnish. 100, 124 
 
 M 
 
 Magnesia, determination of 27 
 
 as a base for printing inks. 79, 127 
 
 Magnetic pigment 70 
 
 properties of 71-72 
 
 use in plate inks 115 
 
 Manganese, determination of 32 
 
 black 70, 72-73 
 
 Matching hues of plate inks 120 
 
 Mills 18, 107-109 
 
 Mineral black 70, 72-73 
 
 Mixed blacks 71 
 
 Mixers 17, 106-107 
 
 Muffle furnace .,..., 16 
 
 Muller and slab 15 
 
 Oil absorption, definition of 10 
 
 effect of in inks 114, 116, 119 
 
 Offset inks 125-127 
 
 pigments for 127 
 
 reducers for 101, 126, 127 
 
 tints of 127 
 
 varnish for 99, 126, 127 
 
 Offsetting of printing inks no, 129, 130 
 
 Oleic acid 101, 102 
 
 Opacity, definition of n 
 
 Orange mineral, analysis of 34 
 
 manufacture of 57, 58 
 
 properties of 58-60, 118 
 
 Organic lakes 84 
 
 control of hue in 85, 86 
 
 developers and fixatives for .... 86 
 
 for typographic inks 121, 122 
 
 manufacture of 84-86 
 
 nomenclature of 88 
 
 properties of 87 
 
 test of 35 
 
 Oven, constant temperature 16 
 
 Paper for printing 114, 115 
 
 Paraffine oil 98 
 
 Paris white, analysis of 26, 27 
 
 manufacture of 80 
 
 properties of 83, 84 
 
 Patent driers 103 
 
 Petrolatum 101 
 
 Phosphates, determination of in 
 
 blacks 34 
 
 Pigments, difference between paint 
 
 and ink 5,6 
 
 for typographic inks. 121, 122, 127 
 
 Plate oils, apparatus for making 95 
 
 from linseed oil 93 
 
 from soya bean oil 96 
 
138 
 
 INDEX 
 
 Plate oils, manufacture of ....... 93~95 
 
 Plate printing inks, defects and 
 remedies .................. 112-120 
 
 - drying of .......... 113, 115, 119 
 
 - - effect of cloths on working of ... 1 14 
 
 - filling in of ......... 113, 114, 118 
 
 - gathering of ____ 112, 113, 115, 118 
 
 - manufacture of .......... 112-120 
 
 - matching of ................. 1 20 
 
 - wiping and polishing of . . 113, 114 
 
 117 
 Primrose yellow ................... 48 
 
 Printing inks .................... 104 
 
 - bleeding of .................. no 
 
 - blending of ................. 105 
 
 - defects and remedies for typo- 
 graphical ...................... 127 
 
 - duotone .................... 112 
 
 - essentials for manufacture . . . 104, 
 
 - gathering of ---- 111,113,115, 117, 
 
 118 
 
 - general classes of ............ 112 
 
 - graining of .................. 1 1 1 
 
 - greasing in ............. 112, 125 
 
 - mills for grinding ........ 107-109 
 
 - mixers for .............. 106-107 
 
 - offsetting of ..... ........ no, 129 
 
 - permanency of .............. no 
 
 - picking up of ........... no, 130 
 
 - plate printing ............... 112 
 
 - polishing of ........ in, 113, 114 
 
 - power press ................. 113 
 
 - rubbing off of ...... 112, 113, 114 
 
 - striking through of ........... 1 10 
 
 - tinting of plates from. . . in, 113, 
 
 "7, 131 
 
 - tints of ........ in, 114, 122, 127 
 
 ^-wiping of. .in, 113, 114, 115, 117 
 
 Red plate inks 118 
 
 Reducers 101, 102 
 
 Remedies for defects in plate inks, 
 
 i i 2-1 20 
 
 Remedies for defects in typographic 
 
 inks 127 
 
 Resinate driers 102 
 
 Rosin, determination of in linseed 
 
 oil 26 
 
 Rosin oil, consistencies of 98, 123 
 
 manufacture of 97 
 
 use in typographic inks . 123 
 
 varnish 99, 124 
 
 Rosin varnish 100, 124 
 
 Rubbing off of inks 112, 117, 131 
 
 Russets . .60 
 
 Saponification number, determina- 
 tion of in linseed oil 24 
 
 Shade, definition of 7 
 
 Shortness, definition of 10 
 
 Soap 101 
 
 Soap driers 102 
 
 Soda, determination of in ultrama- 
 rine blue 33 
 
 Soft black ..67 
 
 Softness, definition of 11 
 
 Soya bean oil 95 
 
 constants of 97 
 
 plate oil from 96 
 
 sources of 97 
 
 Special blacks 71 
 
 Specific gravity, determination of 
 
 in linseed oil 22 
 
 Stearine pitch 100 
 
 Striking through of printing inks. . . no 
 Sulphur, determination of in ultra- 
 marine blue 33 
 
 Tack, definition of 1 1 
 
 Three color process, lakes for 87 
 
 Tint, definition of 7 
 
 Tinting of plates from printing inks 
 
 in, 113, 117, 131 
 
 Tints of printing inks 111-114 
 
 Top hue, definition of 8 
 
 determination of 37 
 
INDEX 
 
 139 
 
 Transfer inks 101 
 
 Transparency, definition of 1 1 
 
 Tungate driers 102 
 
 Typographic inks, manufacture of, 
 
 102-127 
 Typographic varnish. .98-100, 122-126 
 
 U 
 
 Ultramarine blue, analysis of 33 
 
 manufacture of 43 
 
 properties of 44, 45, n8 
 
 Undertone, definition of 8 
 
 determination of 37 
 
 Unsaponifiable matter, determina- 
 tion of in linseed oil 24 
 
 Vehicles for use in typographic inks . 98, 
 122, 125, 126 
 
 Venetian red, manufacture of 61 
 
 properties of 62-63 
 
 Vermillion, analysis of 31 
 
 manufacture of 39 
 
 properties of 40, 118 
 
 Vine black, manufacture of 66, 67 
 
 properties of 72, 73 
 
 Viscosimeters 20, 21 
 
 Viscosity, determination of in oil 
 and varnish 21, 22 
 
 W 
 
 Water, determination of in white 
 
 lead 29 
 
 Water break 115 
 
 White lead, analysis of 29 
 
 manufacture of 76 
 
 properties of 77, 78 
 
 Wiping cloths, effect of on inks 1 14 
 
 Wiping of printing inks . . in, 113, 115, 
 
 117, 118 
 Wood tar. . . . 100 
 
 Yellow plate inks 118 
 
 Zinc green 54 
 
 Zinc oxide, determination of in 
 
 lithopone 28 
 
 Zinc sulphide, determination of in 
 
 lithopone 28 
 
 Zinc white, manufacture of 74 
 
 properties of 77~78 
 
 Zinc yellow 54 
 
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