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 space 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 smut-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 smut-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 smut-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.