CHAPTER II
INTAGLIO METHOD
This differs from the other in that the fat, which is to attract the printing-color, is under the surface of the stone, the design having been either engraved-in or etched, and then filled with fat.
Like the preceding method, it has several branches. The best are these:--
I
THE LINE ENGRAVED STYLE
This is one of the most useful branches of lithography, and if the artist has attained enough skill and the printer knows his trade, it approaches very near to the handsomest copper plates, and at the same time is about three times easier and quicker than work on copper. It is splendidly adapted for writings and charts.
Choose a hard, uniform stone of the best kind. Grind it as finely as possible. Etch with aquafortis and prepare with gum. This, at least, was my early method, and it has remained in use in all printeries. Later, however, I discovered that it is almost better to coat the stone with gum without previous etching, because it can be more easily worked then. Only in that case it must be perfectly clean and contain no concealed fattiness. Immediately after the stone has been coated with gum (not some hours later, as many do) the gum must be removed with water, that it may not penetrate too deeply and thus cause a condition which will prevent the finest lines from taking on color subsequently.
Then coat the plate with a tint made of gum solution and lampblack or red chalk. Use a soft brush to make the coating very thin and uniform. It has the double purpose, first, of giving the stone a color so that the engraver can see his work, and of covering the prepared surface of the stone with a protective coat that later will admit the fatty printing-color only where it has been pierced by the engraving-tool. It is evident that this latter property is increased according to the amount of gum in it, yet only little gum must be used in it, the permissible amount being only just enough to insure that the coating shall not be easily wiped away during the work of engraving.
The stone must be absolutely dry before any work is done on it. Then the design is traced on it, or drafted directly on it with lead. Transfer by printing from paper is not advisable, because the resulting fattiness of the design makes the graver slip.
For the actual work of engraving there is no counsel to be given except to choose good and sharp needles of the very best steel, hard enough to cut glass; and that all lines must be graved clean. There must be no excessive pressure, and in wide strokes there must be no excessive depths. In making very fine lines the stone should merely be touched by the tool. If they appear white, and a little fine dust is observed, one may be certain that they will appear properly in the printing. Broad lines often can be made with one stroke of a flat needle, but generally they are made by continued, gradual scraping. If the stone is to be only lightly wiped during printing, the broad lines must not be deeper than strictly necessary to make them clear, as otherwise they will squash. In true art works, however, which are to be printed with firm color and under more powerful rubbing and wiping, the depths of all lines must be considered carefully, as they will print darker or lighter according to depth.
Of all things the worker must take heed against touching the stone with dirty or greasy hands, for a plate thus blemished is not only difficult to engrave, but the grease finally may penetrate through the slightly gummed coating and enter the stone, making much consequent trouble when the printing begins.
It is more harmful still to wet the stone in any way, because then the coating gum will dissolve, penetrate into the engraved lines and give them a preparation, so that they cannot take color afterward. Therefore, especially in winter, a very cold stone must be warmed before working on it with the design, as otherwise the moisture in the room will precipitate itself on the stone. Even the perspiration of the hands or the moisture of the breath may cause damage. Therefore a good but careful warming is very advisable.
If a plate has become moistened, as, for instance, from a breath, it must be permitted to dry before doing any further work on it, and especially it must not be wiped.
The dust resulting from the engraving is to be removed either with a soft brush or by blowing it away.
Faulty lines that are noticed during the engraving may be scraped flat very carefully so that no furrows are made, or they may be rubbed off with fine pumice, after which those places must be prepared again, and coated with gum applied with a small brush. Then the corrections can be made. If only tiny places are faulty, they need merely be coated with a mixture of weak phosphoric acid, gum, and lampblack or red chalk. This prepares them. Thus they will not take color during the print, and so are practically removed.
When the design is finished, the stone must be very dry that it may take color well. But it must not be warmed, as this would incline it to take smut. A color consisting of thin varnish, a little tallow, and lampblack is now rubbed swiftly into all the depressions, and immediately wiped away again with a woolen rag wetted with gum solution. This removes the original red or black coating also.
Thus the hitherto colored stone becomes perfectly white, while the engraved design, which has appeared white, is now black. The first impression that the eye will gain will be that now the design appears much finer than it did before. That is because every white line on a dark background looks wider than a black line of the same thickness on a white background. Therefore, while engraving, the artist should aim to make his lines a trifle bigger than his eye would suggest.
In printing the stone the usual precautions required in every form of lithographic printing must be observed. Beyond that, the matter of chief importance is the proper composition of the printing-color.
Stone plates made in this way can be inked-in (1) by rubbing-in the color and light wiping, and (2) by harder wiping, and (3) by the ink-roller.
For the first method, a color can be made of thin varnish and burned lampblack, the latter being present in fairly large quantity but very finely rubbed-down. Into this color is mixed a quantity, equivalent to one half the mass, of gum solution that is almost as thick as the color itself. Everything must be mixed perfectly. If the solution is too watery, it is not easy to mix it.
Three clean rags of cotton or linen are needed for inking. The first is used to wet the stone and to clean it again in the end. The second is colored with a small quantity of printing-color and rubbed in by thorough wiping to and fro. The third rag is used to clean away any surplus that may adhere. Then the first clean rag is used to cleanse the stone thoroughly.
All three rags must be wetted with gum solution, and the first and third must be washed several times during the day.
The stone plate is harder to clean at first than after some fifty impressions have been made. Often there will remain little specks of color on the prepared places, which are easy enough to wipe away but are inclined to reappear. To remedy this it may be necessary to use more clean rags in the beginning or more gum solution. If the stone has been polished very well in grinding, this trouble will not be very noticeable if at all. Under any circumstances, it will disappear gradually during the printing, so that at last it will be possible to clean the surface with the very same rag that lays the color on and is permeated with ink.
In the second method, the wiping is harder in order to take more color away from the shallower lines, so that they will be pale compared with the deep ones which then will appear very black and strong.
If the full beauty of a well-made copper plate is to be equaled, care must be taken, as said before, to achieve the proper depth of engraving, and the stone must be wiped harder. Otherwise the method is the same, except that beautiful, shining impressions often can be made by using a firm color, if the stone can bear the necessary tension.
The inking-in with the ink-roller is like the same process in other methods, except that the color must be softer and the roller well filled with it. It is necessary, also, to learn by practice how to work the color into all the deep lines.
The impression must be made immediately after inking, as otherwise the color will sink too deeply into the stone and not give a strong impression without renewed inking.
The paper must be wetted a little more than in the other method.
The tension of the press is according to the size of the plates, but on the whole must be two or three times greater than for the other methods. More pressure still may be needed for very fine work, as the finer lines often are harder to print than the coarse ones.
As soon as the first clean proof is pulled, it must be examined for errors or faults in the design. If there are any, the stone is removed from the press after being delicately coated with gum, and the correction is made as follows: Before anything else, all such faults as are to be removed entirely are either scraped away with a very sharp knife or rubbed away with a very fine stone. The manipulation must be very delicate to avoid grooves and furrows or sharp edges that afterward will hold dirt. Then the parts thus corrected are coated with a mixture of about six parts water, two parts gum, and one part aquafortis to prepare them anew.
If anything new is to be added to the design or drawn in place of an error, the stone is washed with water throughout, or, if the correction is to be made only in a very small part, washed at the desired place. Then it is coated with the red chalk as described in the beginning, but so thinly that the design can be seen plainly through the red coat. Now all that is desired can be engraved, filled again with the rubbing-in color, and turned over to the printer, who cleanses it with gum water and proceeds to print.
Only a few more useful suggestions:--
(1) It happens often that after the first rubbing-in of fat color and the succeeding cleansing with water, the stone gets a "tone" over its whole surface; that is, it takes color at least partly, and thus seems to have lost its original preparation. This may be due to the fact that not enough gum has been used in the original coating, or that the rubbing-in was rough enough to injure the protective coating, or that the rubbing-in-color was left on too long before being washed away with gum solution.
A similar fault may develop with the second rubbing-in, after corrections, and from the following causes: Poor color containing sand; too much pressure with the greasy rags; the use of rags not sufficiently cleansed of any soap used in washing them; rubbing-in of color with too dry a color rag; in brief, from anything that may destroy the stone's preparation wholly or in part.
Sometimes this defect may be remedied by mixing more gum into the printing-color and into the water with which the cleaning-rags are wetted. A firmer color may aid, if it is rubbed away by fairly strong pressure of the rag as soon as it has adhered. This operates as a remedy because the firm color takes hold of the dirt that has set itself into the pores of the stones, and when it is removed, takes the dirt with it. If none of these have results, there is nothing left except to grind off the plate very slightly and carefully with an exceedingly fine stone and gum solution. In the case of very delicate designs, this is not applicable, because the finest lines have practically no depth. Therefore they must be washed instead, a rag being dipped into weak aquafortis or very much diluted phosphoric acid, and passed carefully over the stone till the dirt disappears. It is well to mix in a little gum, and also to rub acid-proof ink into the stone first, that the etching fluid may not attack the design too much.
After this cleansing the tone will disappear, but another fault often appears in place of it. The color, after rubbing-in, will not permit itself to be wiped away readily, because the etching has caused some roughnesses to which the color adheres in the form of little specks. A number of clean rags with gum solution must then be used, or the stone should be lightly rolled a few times with the ink-roller after being rubbed-in. The roller will take the specks. Indeed, the fault hardly ever appears if the inking-in is done with the roller, as suggested in the remarks about the third form of inking-in.
As soon as some few impressions have been made, the roughness of the plate disappears gradually and it can be wiped off without leaving specks behind. Gentle rubbing with pumice finely powdered and mixed with gum solution will remove the defect in the very beginning, but care is needed lest the design be injured.
(2) A line that has so little depth that it is almost level with the surface of the stone can be made as black as a deeply engraved one by continued rubbing with the color rag. In using a firmer color the lines, especially the wider ones, can be so overloaded after a while that the ink will squash under the press. This surplus can be removed again by the use of the ink-roller, but it is merely adding unnecessary work, as proper practice in inking-in and the use of exactly the right consistency of color will prevent the trouble.
(3) The best way to ink-in an intaglio design is to rub it in at first with a somewhat firm color that however, contains enough gum, then to wipe it a bit, and after that to rub gently to and fro over the stone under gentle pressure, with a rag containing a less heavy color. A firmer color does not adhere well to the more delicate lines, or, at least, is hard to print; but by applying it first, the printing of the wider and deeper lines is facilitated, while the succeeding rubbing with softer color brings out the perfection of the finer lines.
The second rag with the lighter color must not be filled with it in mass, but should merely be made sooty with it, so to speak. Otherwise the lighter color would penetrate the deeper lines also and mix there with the heavier color.
In the end the stone must be wiped again with an entirely clean rag, as will be understood, of course, and thoroughly cleansed of all the color.
II
THE ETCHED METHOD
In this the design is not engraved into the stone by pressure of the hand, but with aquafortis or other acid, and only so much pressure is exerted in making the design as is required to cut through the thin coating of varnish with which the stone is covered. Therefore this method permits great freedom of action and is applicable especially for landscape work and for drawings in Rembrandt's style. In treatment as in effect it resembles copper plate, and has its own advantage in that the lines may be strengthened gradually by stronger pressure on the engraving-needle. They may even be engraved a little into the stone so that afterward the lines will become stronger under etching. This cannot be done with copper at all or only with great difficulty.
These considerations and the quicker printing permitted by it recommend the method to artists. In other respects it is not different from working on copper. But it is necessary that a good lithographer should be a master of this form of stone work, as it may be used for excellent work, not only by itself but in combination with the other methods.
The stone must be ground as smoothly as possible, then treated with aquafortis and coated with gum, so that its surface thus is completely prepared. The aquafortis may be as strong as that used for etching pen work. It suffices, also, to wipe the plate merely with a sponge dipped in stronger aquafortis, the chief point being that no roughnesses shall be caused by uneven etching.
A few minutes after this first operation is finished, the stone is rinsed with water, dried and coated with etching-ground. This can be best done as follows:--
(1) Warm the stone till an ordinary copper etcher's etching-ground will become so fluid on it that it can be worked with a leather ball like a varnish, and can be spread very thin and very evenly. Great care must be exercised lest uneven warming crack the stone. If one can put it into a nearby baker's oven, it will obviate the necessity for an especial apparatus, which otherwise is demanded.
After coating the stone with the etching-ground, it is reversed while still warm, and blackened by applying the flame of a tallow or wax candle, as the copper-plate etchers do with their plates. Then the stone is set aside to cool, with great precautions against dust. After it is cool, dust will not harm it, and it can be kept indefinitely before use, so long as the coating is protected against injury.
(2) The method given is the best; but if the warming of the stone is difficult, there is a method applicable to cold stones. The etching-ground is dissolved in oil of turpentine and laid on the stone with a clean ball. A stone so treated must be put away for at least a day in a place safe from dust that the oil of turpentine may evaporate.
To tint this etching-ground, it may be blackened by smoking with a candle, as in the first case; or color, such as lampblack or vermilion, may be mixed-in before it is applied. If one wishes to be very certain that the stone will bear the etching well, it may be coated, very thinly indeed, with a solution of very firm chemical ink after applying the etching-ground.
The design is traced through this coating to the stone. It may be transferred, also, but in that case, as soon as the transfer is on the stone, it must be coated thinly once more with a solution of chemical ink that does not, however, contain any lampblack or other coloring-matter, but is transparent. This is necessary to fill out any little holes and other injuries that may have been caused by the pressure during transfer or by the inequalities in the transfer paper.
The designing with the needle is done as in the engraved manner, except that the design is merely cut into the coating.
When the design is complete, the stone is laid into the etching-trough and diluted aquafortis, muriatic acid, or strong wine vinegar is poured over it repeatedly, according to the depth that the lines are to have.
If it is desired to etch so as to produce various tones,--some strong and some delicate,--after the manner of the copper-plate etchers, the pouring of acid should cease as soon as the very finest lines of the design have been etched sufficiently. Wash away every bit of acid with clean water and let it dry. Then, with a small brush and chemical ink, coat all parts that are not to be etched further. It is well if the chemical ink used for this purpose contains a little more soap than usual, so that it can penetrate well into all the depressions and leave no little holes. The coating must be done very cautiously, and it is better to paint on too much ink rather than too little, as the design will appear very dirty if etching fluid should penetrate here or there through the coated portions.
When the ink is dry, etching is resumed till the second tones have been etched as far as desired. Then the procedure is repeated, these second tones being coated. Thus one continues till all gradations of shading have been reached.
When the stone is fully etched, clean water is poured over it, and then all the parts that have not been coated with chemical ink are treated to a covering. The object of the previous coatings was to prevent access of acid to the parts; but at the same time the ink prepared the parts. Therefore the remaining portions of the design also must be sated with ink before the stone is inked-in for printing.
Let the stone dry and then pour on it as much oil of turpentine as may be necessary to dissolve this whole ground coating, which then is wiped off with a woolen rag wet with gum solution. Then the stone maybe inked-in and printed.
If an error is observed before etching begins, the first question is if the defect is deeply engraved in the stone or if it has been drawn merely through the ground coating without affecting the stone itself materially. In the latter case it is necessary merely to cover the defective place with chemical ink and draw into it the correction. If the error has been graved deeply into the stone, it must be covered for the time being, but nothing new can be drawn there. To do this, one must wait till the plate has been etched and rubbed-in with color. Then the incorrect part is scraped or ground off as evenly as possible, the place prepared anew with aquafortis and gum, and the correction made with the steel needle.
An intaglio design often is greatly beautified by being printed with a tint plate like a crayon design. It can be done with a second stone, but it can be obtained also with the one plate that has the design on it. Wash the designed stone with clean water and then paint a thick coat of chemical ink containing more soap than usual over the whole stone or over only such parts as one desires to improve by adding a tone. If lights are to be worked into this tone, it can be done, after inking-in, with a small brush dipped into weak aquafortis.
In printing a stone thus toned, it must be rubbed-in thoroughly with the black color and then cleaned as well as possible. The tint that shows on the surface then is usually too dark, and the firmer the color the darker it is. Then a second rag must be used with a much softer color, which may even be thinned-down with plain oil or butter. It may also contain another coloring substance. Rub this rag very gently to and fro without much pressure till it is apparent that the dark tone has been replaced by a light one. Then the stone is ready for printing.
Stones to be treated to a tint in this manner must be etched somewhat deeper than others, because the lines do not appear so dark against a tone.
In all intaglio methods there is the advantage that parts that turn out too dark can be modified by fine scraping or grinding. The stone merely must be rubbed with acid-proof ink beforehand, that the necessary preparation of the corrected places with aquafortis or phosphoric acid and gum may not attack the rest of the design. Those who attain skill in scraping or grinding with a small piece of black slate can make the softest gradations of shade in uniformly etched designs, and more easily and quickly than by drawing or coating and etching. If the stone has been rubbed-in with color for the first time only a short time previously, the ground or scraped surfaces do not even need to be etched. It is sufficient to wash them with a rag wetted in gum solution, because the color will not have penetrated the stone so deeply that it is likely to reappear.
III
DESIGN WITH PREPARING INK, COMBINED WITH SPATTERED AQUATINT
If a little dissolved gum is painted on a clean stone that then is inked over its whole surface with printing-ink, none will adhere where the gum is. In other words, the stone will have been prepared there. If the gum is permitted to dry before the ink is applied, those parts will become black, too; but as soon as a few drops of water are poured on and the ink-roller passes over the stone, all the gummed parts will show up white at once. This led me to make a color mixed with gum, with which one can design on stone and that would have the property of preparing it so that, on printing, the design or inscription will print white.
Some drops of gum arabic dissolved in water are mixed with an equal amount of lampblack and rubbed very fine. This makes an ink similar to Chinese ink, and keeps well when dried. It is rubbed down in a saucer with a little water and then is ready for use.
It can be used on a clean stone, but is likely to flow, for which reason the stone must be painted with a little weak aquafortis mixed with a little nutgall, and then well cleaned again. Still better is it to paint a clean stone some days before with oil of turpentine which is cleaned off again immediately. In that case, however, it is well to mix a little phosphoric acid into the drawing-ink, that the designed parts will be prepared the more surely.
When the design is dry, the whole stone is inked with printing-color, care being taken that not a drop of water touches it before it is perfectly black. Then a little water is poured on, after which there must be a little more rolling with the ink-roller till all the design that is drawn with the preparing-ink is very white and clean. Now the stone can be used for printing, being used in the manner used for pen work. To make the design more durable, that it may not in time thicken in its finer parts, the stone may be well inked-in with acid-proof ink and after a few hours, during which it draws together well, the drawing is etched in intaglio with aquafortis. Then it is coated with gum and the printing is not likely to damage the design.
Here we have an intaglio design which is prepared and prints white.
The case may be reversed, and the black plate may be made white again while the design will print black. This is because a stone treated with preparing-ink gives almost the same result, once it is grounded with acid-proof ink and etched as if the design had been engraved into etching-ground. The etched lines need simply be filled with chemical ink as in engraved work, to make them take color instead of coating them with gum. Then there remains only the obstacle that the stone is not prepared over its whole surface and takes color everywhere. However, it is not difficult to clean the plate and prepare it perfectly, especially if the stone is finely polished. It must be rubbed well with color, and wiped clean at once without rubbing too much of it away from the etched design. To make the color easier to wipe out, Frankfurter black and tallow may be mixed in it. Then the rag that has been used for inking-in is dipped into a mixture of twenty parts water, two parts gum, and one part aquafortis, or better still, phosphoric acid, and rubbed back and forth. The rag must not be too dirty and heavy with color, but it must contain some so that the delicate parts of the design shall not be wiped out and thus rendered susceptible to the acid. The next thing is to try with the finger to see whether the color on top can be easily rubbed away or not. In the latter case the wiping must be repeated till the cleansing mixture has so far prepared the surface that the wet hand or a wet piece of leather can cleanse it perfectly and free it from the dark tone. Now the stone is inked-in with firmer color (acid-proof ink is best). This is wiped off again thoroughly. Very weak aquafortis (or phosphoric acid if it has been used for the work) is then poured over it a few times, and this generally prepares it so well that it can be inked and cleaned easily during the printing.
This method is useful for many kinds of art, and it must not be imagined that it is superfluous because the other ways are quicker.
The engraving-needle is very good for drawing the finer parts of the design through the etching-ground, but the coarser ones cause much trouble, while with the pen, these are the very ones that are easiest to produce. By using this method, both advantages can be combined and only that is drawn with the pen which is most readily produced that way.
Thus the whole design, with the exception of the finest parts, is drawn on the white plate with the black preparing ink touche. Then, when it has been covered with acid-proof ink and made white, the finer parts are worked-in with the needle. Or they may be left till the end, when they are engraved-in.
For grounding or blackening the plate, one may use a substitute for the acid-proof ink if the ground is to be firmer. Use the etching-ground (mentioned several times before) of wax, mastic, pitch, and resin, dissolved in oil of turpentine and mixed with fine lampblack. It will then be susceptible of being laid beautifully uniform on the stone with the ink-roller like printing-ink.
The spattered aquatint method resembles this.
The outlines of the design are engraved or etched into the stone very delicately. After rubbing-in with black printing-ink and cleaning again thoroughly, it is rinsed with a great deal of clean water to take away every trace of gum. When it is dry a small brush is dipped into the preparing-ink, and the stone is spattered as described in the article on spatter-work. After drying, the dots that are too large are treated with the needle, and missing ones are drawn in with the pen. Now apply the roller with the dissolved etching-ground, that must, however, have only enough color so that the outlines of the design can show through it. Then the spattered work is brought out by rolling with water. Now coat the lighter parts of the design and etch. Coat again and etch again, in short do as already described for the method of successive etching till the required gradations of shade have been attained. Then proceed as usual with the inking-in and printing.
IV
AQUATINT IN COPPER-PLATE STYLES AND WITH ETCHING-GROUND
Any one who has the necessary appliances of the copper-plate worker for making the aquatint ground used by them, and who has the necessary skill, can do so, although the stone is endangered by the heat, and the process is not advisable. The stone is dusted with fine resin. A flame of spirits is applied below until the stone is so hot that the resin melts and forms the ground.
Better is that copper-plate method in which the resin is dissolved in highly rectified spirits of wine and poured quickly over the whole stone. By breathing on this, the resin is made to separate from the spirits and form tiny pellets, which thus make the required aquatint ground.
Both methods are better for very coarse work than for fine designs. Etching-ground, dissolved in oil of turpentine, or consisting simply of tallow and put on the stone very uniformly with a cotton ball, is much better, and produces an effect similar to wash drawing. However, it is better suited to the lighter parts of a design, because it will bear long and powerful etching only if one hits exactly the proper proportions between ground and etching fluid. Therefore, it is well, after the first tones have been etched and printed, to spatter cautiously with chemical ink all those parts that are to be darker than half-tones. Thus these dots will prepare the design so well at those places that they can withstand the most powerful etching.
V
AQUATINT THROUGH CRAYON GROUND
This is a sort of middle process between aquatint and the scraped style. It has the advantage of great speediness.
A stone that has been grained for crayon work is coated with the black or red gum ground described for the engraved method, but without previous etching, which would not do harm but is unnecessary. The outlines are drawn in with the needle very lightly, because they are to serve only to make the design visible. Those lines, however, that are not to disappear in the aquatint tone, but are to show plainly, must be cut as deeply as necessary for greater or lesser blackness. Then the stone is rubbed with color and washed with water as in the engraved method.
When it is entirely clean and dry, all the design will be black and the stone white. The design must be examined carefully, and the various gradations of shading should be separated in the mind into about eight leading classes, of which four are numbered upwards to the lightest parts, and four numbered downwards to the darkest. Everything in the category of the four dark parts now is worked strongly with chemical crayon. The purpose is to mass a number of evenly separated points over these parts of the design that shall withstand the etching fluid like an aquatint ground, between which the etching fluid may eat the stone and thus form a coarser grain than could be attained merely by rough grinding.
Then the four lighter parts must be coated with chemical ink. The very lightest parts, and all that is to remain white, must be left white on the plate and neither touched with crayon or ink.
Then the stone is etched for the first time. Following this pour clean water over it and let it dry. Then of the four dark parts the lightest are coated with chemical ink, and when it is dry the etching fluid is applied again. After washing and drying, the next lighter portions of the dark sections are coated, and so on till at last the very darkest shadows have been coated. Then a clean brush is dipped into gum solution and everything that should remain white is painted.
If a little oil of turpentine is now poured on the stone, and the crayon and chemical ink are dissolved and wiped off, the stone can be inked with soft inking-color and wiped again with a woolen rag. Then the design will look as if a black veil were over it, because the lightest parts of it and the half-shadows are not worked out at all. Wet a rag with gum solution and a little phosphoric acid, and hold it in one hand while with a fine scraper you scrape in the lights according to their gradation or grind them in with a fine stone, for instance, a slate pencil. As you scrape wipe over the design with the wet rag; and you will see exactly what you are doing as the various gradations will appear bit by bit. The printing in this as in other aquatint methods is done with soft and thin printing-color, and the paper may be more dampened than in other forms of lithography. The press needs considerable tension and the stones must be thick.
VI
INTAGLIO CRAYON AND TRACED DESIGNS
The difficulty of getting impressions from crayon that shall not differ from the original design on the stone led me to consider the use of the grained style of the copper-plate engravers. A crayon-like design in intaglio would have a greater strength in the dark parts and greater delicacy in the lighter; be more durable and more easily corrected. I saw at once that if I could attain some perfection, it would mean a great step forward in color printing, also. Thus there were originated the following two processes, which no doubt will in time interest artists to a high degree.
A stone grained for crayon work is prepared with aquafortis and gum. Then it is cleansed with water and covered with etching-ground when dry, as is prescribed for the etched process. The ground must be laid on so thinly and evenly that the design can be put in easily and that it still will resist the etching.
When the stone is cold and the outlines of the design have been traced on it, a scraper of the best steel is used to scrape in the lights and shadows. The scraper touches only the most elevated points of the grained surface at first, and produces larger points only after continued work, just as chemical crayon does. When the whole stone is finished, it is etched as in the etched process and then cleansed and printed in the same way.
If the stone is etched a little more strongly in all its gradations, it can afterward be ground down gently with very soft pumice, or, better still, with black slate and a gum solution, once it has been rubbed-in with color. This destroys all roughnesses that may remain from the first manipulations. Parts that have turned out too dark can be lightened by this polishing, and the over-light ones can be improved with the needle.
The designs made in this manner possess more delicacy as well as more strength than the ordinary crayon designs, and there remains to be desired only that they might have the advantage of the latter of being worked black on white, as it is so much easier for the artist to judge his work on the stone.
Of trials made in this direction, the two following ones met my views the best.
One way is to grind the stone rough, pour diluted aquafortis and nutgall over it, clean it with water and dry it. Then the design is drawn on it with a black chalk made of oil of vitriol, tartar, and lampblack. The further treatment is the same as that in the case of designs done with preparing-ink.
I have not been able to give enough time to this process to invent a preparing-crayon that shall be very hard without losing its preparing-property. However, the compound mentioned will produce a crayon with which one can work well after a few days. It has the advantage that it may be rubbed on a shading-stump made of rolled paper, which will prove excellent for working the finest shadings into the plate.
The other way is as follows: A colorless chemical ink is made of one part wax, two parts tallow, and one part soap. This I dissolved in water and with it I coated the stone, which had been ground rough and prepared with phosphoric acid, nutgall, and gum, and then washed with water. The coating was applied very lightly, but enough so that it could bear the succeeding etching.
As soon as it was dry, I drew the design on it with a black crayon made of tartar, gum, a little sugar, and a good amount of lampblack, or I used the ordinary black Paris crayon or a fine English lead pencil. Then the design was etched, after which alum water was poured over it, and it was set aside to dry.
As soon as it was absolutely dry, I coated it with fatty color, and then cleaned the stone with oil of turpentine and gum solution. If I wanted an exceedingly smooth surface, I ground the stone gently; but then the design had to be etched deeply.
The good results of these two experiments led me to the following process: By following my instructions exactly the worker can produce striking imitations of wash as well as crayon drawings, and at the same time unite the greatest possible ease of drawing as well as certainty of good impressions, so that this process really deserves to be called one of the very best of all printing-methods.
The outlines of the drawing must be drawn on the finest and thinnest paper that can be obtained. Then a very finely polished stone is prepared with aquafortis and gum, or, better still, with phosphoric acid, nutgall, and gum, cleansed with water and dried. Then it is coated very thinly with tallow, which is patted with a very clean leather ball or with the hand, so that it shall be very uniformly laid over the stone. Everything depends on the thinness and uniformity of this tallow coating. Then the stone must be smoked with a wax torch or a tallow candle. The durability of the ground depends on this smoking, as without it a very thin coating of tallow would be penetrated by the acid.
Now the stone is ready for the design. It must not be touched by so much as a finger. The designed paper is pasted to the stone at the ends, without pulling, as the least motion would injure the stone's surface. The arrangement of elevated supports for the hand (previously described) is needed for the succeeding work. The drawing is then done on the paper with Paris chalk, delicate Spanish chalk, an English lead pencil, or with a small piece of lead. All that is drawn on the paper will impress itself on the stone underneath and remove the ground at those places, thus opening the surface for etching.
When the drawing is finished, it is etched and covered as with the etched process, and afterward is printed as in that process.
When sufficient practice has made one a master of this style, it will be amazing what great perfection, what miniature-like delicacy, and also what strength can be obtained by proper etching.
Besides, this latter process is applicable in combination with the etched process.
VII
TOUCHE DRAWING WITH ETCHING INK
This method is very useful for filling-out etched or engraved designs, also for correcting and completing the various aquatint processes.
Dip a little brush into lemon juice mixed with a little lampblack and draw the design on the finely polished and prepared stone. The acid will eat little holes into it, which will take color if the lemon juice is washed away as soon as it has completed its etching, and the etched part has been dried and rubbed-in with fat color. To produce darker shadings it can be laid on the same place twice, and for lighter shadings the acid either is washed away sooner or diluted with water.
I do not doubt that a skillful chemist could invent an etching ink which would be even more perfect, and then a drawing could be washed on the stone as easily as on paper, which would mean immense advance for the art.