The Invention of Lithography Part 21

If pen and brush work are to be combined on a stone, and absolute certainty is desired, that even the very finest lines shall not suffer from etching, the following process will serve:--

Over the cleanly ground plate pour a solution of weakened but pure aquafortis, about forty parts of water to one part of aquafortis. Repeat this several times. Then pour a great deal of water over the stone, to wash off all acid, and let it dry. Pen as well as brush work is easy on such a stone, by using the proper ink for each method. When the work is finished and dry, the stone is merely coated with gum solution. After a few minutes it can be inked-in with acid-proof ink and treated as described before.

II

THE CRAYON METHOD

The fat of the chemical ink penetrates the stone in dry form as well as in fluid form, and makes the plate receptive to printing-color. If the dry ink is cut into long pieces and sharpened, it can be used much like lead or black crayon. If the stone is ground very smooth, the work can be made quite fine and resembles that done with fluid ink. The crayon, however, wears away too quickly. If the stone is ground rough, so that instead of a polished surface it has one resembling rough paper, the crayon work appears as a ma.s.s of dots that are coa.r.s.er or finer according to pressure with the crayon, and produce an effect similar to crayon designs on paper. As almost every artist and painter knows how to use crayon, no particular practice is required for working on stone, and there are no obstacles such as the difficulty of using the steel pen.

That crayon work on stone is capable of high perfection, and that it can represent the essentials of a painting in a manner scarcely to be excelled by the best copper-plate engraver, has been demonstrated by many successful productions. Add to this that in no other style can one work equally fast, either on copper or stone, and we see that the crayon method is a genuine advantage for the art.

For crayon work the stones must be uniform and hard. They must either be new, or, if they have been used, they must be ground so thoroughly that all traces of fat are destroyed and removed absolutely to a degree where it is certain that they will not appear again and take color, even if the stone is etched only lightly. As soon as the plates have been ground true, they must be grained by strewing some fine sand or powdered sandstone on them and rubbing in all directions with a small piece of limestone. The work can be done dry or wet. Soap-water is best. It gives the stone a handsome grain. Practice is demanded to get good results without scratching the stone. The artist must decide for himself what grain he needs. I think that it would be good if the artist himself were to grain the stone in varying degrees according to the need of his design. For instance, a coa.r.s.er grain might be good for foregrounds.

As soon as the stone has been grained, it must be cleansed perfectly from dust and dirt. It is best to pour clean water over it and wash it with a clean rag. The dust and sand must all be removed, otherwise they will not let the crayon reach the stone where it is used delicately.

When the design is finished, it should be set aside for a day, that it may take good hold of the stone. It does no harm to let plates rest for years before etching. Etching must be done by pouring. Painting the etching fluid on is dangerous because of the danger of taking away fine spots. About one hundred parts of water are used to one part of aquafortis. Everything depends on not etching a bit more than necessary.

It is best to etch the coa.r.s.er parts specially with a small brush and stronger etching solution, and it is very good to wash the stone with clean water after etching and let it dry completely before coating with gum.

When the stone has been prepared, it should not be cleansed at once with oil of turpentine, but should be inked-in first with a light printing-color. Only after it has taken this well should it be cleansed of the crayon and treated to a firmer color. In the first inking-in there should be very little pressure with the sponge or wet cloth when dampening it, as the lightest parts of the design are easily rubbed away before they have taken color. If such parts should vanish, the easiest way to restore them is as follows:--

Coat the plate with gum solution and wipe with a clean dry cloth till it is perfectly dry. Then take a flat, knife-like instrument of steel, which is cleanly ground so that it has no nicks or other defects that might injure the stone. Sc.r.a.pe with moderate pressure to and fro over the defective places, but only so that it touches the elevated points and not the surface of the stone itself. Smear a little fat, such as linseed oil varnish, over it and wash this away again instantly with gum solution. Generally the parts all reappear very nicely when the stone is inked-in again.

A second kind of correction is as follows: Ink the stone with firm color, wash it well with plenty of pure water and let it dry. Now redraw the lost places with crayon.

Printing crayon work is the most difficult of all lithography, but can be done perfectly if all necessary precautions are taken. These are mainly: (_a_) proper dampening of the paper; (_b_) perfect dampening of the stone;--too much meaning that the fine points will not take color well, too little making the stone s.m.u.t easily; (_c_) good stretching of the leather, industrious lubrication, and an underlay of taffeta; (_d_) a good, finely mixed inking-color that will not shade off in printing and yet does not contain too much lampblack; (_e_) soft and well-dried ink-rollers; (_f_) proper tension of the press; (_g_) utmost possible speed in printing. The latter aids enormously, because the stone does not get so much time to dry out.

Aside from the spreading and running-together of the darker parts, one of the commonest faults of crayon work is that it is very liable to get a tone, which spreads over the whole design like a veil; or that the designs lose their firmness and appear "monotonic" because the shadings spread and thicken. The first fault comes from weak etching or from oil that was rancid when it was used to prepare the varnish. The latter fault makes the color adhere and s.m.u.t the stone. The same fault is developed if the printing-color contains soap, which some printers mix into it for better adherence. It can occur also if the stone has lost its preparation owing to frequent cleansing and strong rubbing with a dry rag that is inky. Even strong rubbing with clean water can cause it if the rag contains fats.

As to the "monotonic" effect, it is frequent, and I have learned that it can be caused in two ways, namely, if the color is squashed continually during the print, which makes the stone sooty; or if the color spreads, as, for instance, during the night or during the noonday rest. The stone is prepared only on the surface. In the pen style, all lines are prepared on the sides also, so that they cannot spread because they are considerably more elevated than the crayon designs.

If a crayon design dries after printing and is not coated properly with gum, the color is liable to spread away from the design and give the plate the before-mentioned tone. Even if it is coated with gum, the color will spread, at least in the inner parts of the stone; and as soon as the very thin surface has been at all wiped away by rough usage, the underlying fattiness will appear gradually, and begin to take color.

Both faults of crayon work, namely, the taking of tone and the development of a "monotonic" condition, can be remedied by inking the plate for a while with a firmer color. If this does not help, the following must be resorted to: Ink-in the plate as well as possible, lay it in the etching-trough and pour over it very weak aquafortis once or twice. Then wash it with pure water and paint the gum solution over it.

The etching must be done with great caution, with a solution so weak that the acid is scarcely perceptible. If the plate is to be saved at all without extensive corrections and re-drawing, this is the best way.

If it is done correctly, it harms the design so little that I advise it even when the plate looks quite well, but has been standing very long after the first printing.

I have etched several crayon designs over again, and rather extensively, to make them more durable and facilitate printing, and with good success. This gives the further advantage that corrections can be made at the same time.

The correction of crayon designs, that have been etched already and used for printing, always has been so difficult a task that few have succeeded. This has led me to give the matter my best attention; and I hope that the following rules, based on many experiments, will show the way, at least, even if they do not produce absolute results.

When a copper-plate engraver has partially finished his plate, he can have a proof pulled to enable him to study his work. Then he can make corrections as he pleases,--an advantage that the stone worker has lacked hitherto.

To produce an impression that shall be faithful to all the beauties of a crayon design is a matter dependent on so many trivial details that of the many hundred crayon designs that have been produced by lithographers since the origin of the art, hardly one has realized the designer's hopes and ambitions. The commonest fault is that the more delicate parts of the design print too light and the heavier ones too dark, thus destroying the balance of tones. The lightening occurs because the finest parts of the design have lost their power of taking printing-color. The darkening occurs because the closely shaded parts flow together, either because the etching has not made enough white s.p.a.ce between the points and lines or because they are squashed in the pressure of printing.

From this, two other faults may arise, that become visible after inking-in the plate: The first is the appearance of white dots, sometimes pretty large. The second is that black dots and s.m.u.t-marks appear.

The white dots are caused by speaking during the work, and thus dropping spittle on the plate. If the spittle is mucous, the plate covers itself there with a fine crust that resists the chemical crayon so that it does not soak into the stone and is wiped away by the inking-in. If the spittle is fatty,--for instance, if one has eaten anything greasy,--the dots that appear will be black. The same results from touching the plate with fatty hands. Sometimes a whole picture of the fingers and skin will appear on the impression.

Let us suppose that after inking-in, a plate shows all these faults: the finest shadings vanished entirely, the darker places run together, white and black dots and s.m.u.t-marks so that the plate has become useless in every respect. Can this be remedied? If so, how?

I answer that it can be remedied in every point; but that the artist himself must decide if it will not pay better to do the whole design anew.

The second question I answer as follows:--

Before everything else, it is necessary to remove all that should not be on the stone, all s.m.u.t-marks and black dots; and where the design has darkened, white points or lights must be graved-in. To accomplish this, the stone is inked-in first with a firm acid-proof color, and over this with a lighter one. Then erase or grind away the dirt that is outside of the design and that would dirty the margin of the printing-paper. No erasing or grinding must be done within the design itself because then the grain would be destroyed and the necessary drawing could not be done as it should be. Therefore the faulty parts must be removed by engraving, with a more or less sharp needle of good steel, so that what remains looks quite like a good grain. A little practice will show that this work is not at all difficult and can be done quickly. Places that have run together can be cleared and made transparent and clean in a few minutes. If certain points have become too large, they can be corrected by engraving a white point in their centre or by engraving a line through them.

Here I must note that parts of crayon designs thicken sometimes because the crayon has slipped in drawing, without leaving traces perceptible at the time. If the etching is weak, it may happen easily that this place takes printing-color. Skillful engraving may not only correct the defect, but actually gives the design a beautiful tone and power such as cannot be easily produced by the crayon itself.

When the plate has been cleansed thus of all surplus and blemishes, weak aquafortis is poured over it several times and then it is coated with gum. After a few minutes it is inked-in with fairly firm color. Then it will be seen that the design is clean, but that all the parts that were too light are not darker, but perhaps even lighter, having been affected by the etching. To remedy this, coat the stone with gum solution and then wipe it off with a dry clean rag so thoroughly that only a thin film of gum remains behind. To judge this better, it is well to mix a little red chalk with the gum. When the plate is wholly dry, take a knife-like tool of steel as described before, and sc.r.a.pe the defective parts under moderate pressure, without injuring the elevated points of the design. Great care must be taken during this process to let no moisture, not even the breath, touch the stone, because that would produce the very opposite of what is aimed at. When all faulty places have been treated, a little tallow or linseed oil is smeared over the plate and then washed away well but gently with thin gum and water. If this manipulation has been done accurately, the lost parts of the design will appear when the plate is inked with a somewhat softer color.

Those who fear that they do not possess the skill necessary for this rubbing-up of the defective parts may attain the object by re-drawing them. The stone must be washed off first with a great deal of very pure water and the crayon must contain much soap. This kind of correction must be finished as quickly as possible and the stone should not be set aside for any length of time without a gum coating. If the corrections are extensive, it is better first to ink the stone well with acid-proof color and then to wash it in pure water and let it dry. Then if it is inked-in after the design is finished, and if weak aquafortis is poured over it and it is prepared with gum, it will keep for several months.

Slight blemishes, white specks, etc., can best be corrected by gentle touching-up with crayon during the proof-printing on the wet plate. It is understood, of course, that one can also work with pen or brush in a crayon design that has been already etched. Parts that are too dark can be made lighter by pa.s.sing over them a few times with a brush dipped in weak aquafortis and then re-coating with gum.

These are about the best ways for correcting a crayon design that proves after etching to be imperfect.

I close with the following:--

(1) The tanners of Munich manufacture an inking-ball, made especially for printing, of sheepskin, such as I could not obtain in other places, like London, Offenbach, and Vienna. It is not white like alum-dressed leather, but yellowish, and the oil has not been completely washed out.

I have had dogskin and thin calfskin worked in the same way and have found them even better, because of their greater durability. If a roller is covered with this leather, so that the side that was hairy comes outermost (not innermost as many do), it develops a decided property of taking-on color, probably because of its smoothness and elasticity. This aids much in spreading the color uniformly over the stone. The property is increased if the roller is dampened slightly before being inked; but on the contrary, if the stone is kept too wet, the constant moisture will gradually prepare the roller, so to speak, and it will take less color and let it go quickly, thus inking the stone badly.

If a roller has been used a long time, it loses its elasticity and softness and becomes useless for fine work. Still worse is a roller that has hardened from the drying of the ink. It is surprising to see what a difference it makes if one has worked for a time with a poor roller and then replaces it with a good one. It is almost impossible to believe that the new impressions come from the same stone. I am inclined, therefore, to believe that the quality of the ink-roller has more effect on good impressions of crayon and fine pen work than even the quality of the printing-color.

As stated, it is well to change rollers frequently, and it is wise to clean them with linseed oil or b.u.t.ter after use to keep them soft and tender. In working on crayon designs of superior value I advise the use of new rollers.

(2) It has been remarked before that the color of the stone often deceives the artist as to the values and proportions of his work and that the designs always look better on the soft-colored stone than they do on the glaring white paper. This observation led to printing on paper tinted like the stone, and the results fulfilled expectations. There were difficulties however. The very best quality of this paper is extremely dear, and other qualities had the property of dirtying the stone, on account of the coloring-matter used for tinting them.

Therefore the attempt was made to print the design on white paper and to color it afterwards. Here, too, there arose many inconveniences, so that at last there came the thought of laying a yellow tint over the impression by means of a second printing. This method proved to be not only the most economical and quick, but it had the further advantage that the margins of the paper could be left white, thus enhancing the value of the design. Hardly had it been used with success a few times before Herr Piloty conceived the idea of printing the high lights into the design with white printing-color, so that the impressions would resemble actual drawings. My experiments toward that end did not result satisfactorily, because no white oil color will print well enough; and I proposed that the high lights be engraved into the tint plate and thus permit the original white of the paper to show. So there came that kind of crayon impression with one or more tint plates, which has become so popular that various art connoisseurs hold it to be the triumph of the lithographic art.

To make and print these tone plates, I have thought out many ways; but as I am sure that they will suggest themselves to those who have grasped my text-book, I will describe only the best of them all.

Take a stone of good average quality, the best not being essential, and grind it as for crayon work with a grain not too coa.r.s.e. When it is clean and dry, cover it uniformly with the following chemical ink, which must be laid on so thickly that it surely will resist the aquafortis sufficiently, yet not so very thickly that it will hinder the drawing-in of the lights later on.

The chemical ink for use on the tone plates is made of four parts wax, one part soap, and two parts vermilion. The two first materials are melted in a clean vessel over a moderate fire and then the vermilion is stirred in.

A piece of ink as large as a hazel nut is rubbed down in a clean coffee cup and then dissolved in rain water till it is just fluid enough to lie evenly and nicely on the plate when applied with a soft brush.

When the stone thus has been painted red, it must be permitted to dry thoroughly. When it is dry, a strong impression of the design is made on sized but well-dampened paper with a printing-color rather soft than firm. Before the paper has a chance to dry and thus to shrink, the red stone is placed in the press and the impression is laid on it face down.

Use moderate pressure. The drawing will transfer itself to the red surface, but the paper will stick. Wet it with weak aquafortis till it is completely softened and permits itself to be removed. Care must be taken not to spoil the drawing by violent wiping and rubbing.

This method is easier if a special transfer paper is used. Coat well-sized, very clean paper with a thin paste of starch such as laundresses use for stiffening linen. This paper must not be dampened very much, because then it will not take the impression well. It also is removed from the tone plate by was.h.i.+ng with weak aquafortis and it yields very easily, because the paste lets go of the color readily.

When the design has been transferred to the tone plate, take good iron instruments and remove the wax surface wherever the high lights are desired. As the stone is ground rough, the sc.r.a.ping will produce only small specks at first, because the instrument will touch only the relief points. The more the sc.r.a.ping proceeds, the deeper it will go, till at last one reaches the bottom of the coating and thus obtains a white light. Experts can so manipulate the tint plates that the lights will be graduated from the softest to the most glaring.

As soon as the lights are drawn in, the margins of the drawing are sc.r.a.ped the same way. Then the plate is treated to several was.h.i.+ngs of pretty strong aquafortis, about twenty parts of water to one part of aquafortis. After coating with gum, it is ready for printing.

The most important requisite for this printing is a good arrangement that will insure an exact register of the second impression with the first, that the lights may appear exactly where they belong.