Now the plate is to be dusted with the finest pulverized resin, consisting of equal parts of Syrian asphalt, washed in alcohol, and of mastic; the superfluous resin is removed with a brush and some cotton; the plate is then carefully heated, without beginning to melt the resin, however.
This, by the French method, finishes the plate for etching. Only weak acid is safe for such a plate, however.
According to the Austrian method (practised by me for several years), we proceed as follows: The copied plate is first copiously coated with a cold saturated solution of gallic acid, and then with a pure solution of gum. Without allowing it to dry, I remove the superfluous preparing materials with a wet sponge, and pour on some fresh gallic acid, as with an excess of acid the drawing assumes a more brilliant black color.
The strengthening with ordinary copying color I effect, as the case may be, with the rollers, the sponge, or by coating.
(a) Strengthening with the Rollers.—I roll out some thick copying ink with good, rough rollers which have been frequently used, and begin to roll the transfer plate while still damp, without any pressure, till its surface begins to dry. I then grasp the handles of the rollers more firmly and blacken the dry plate uniformly, giving it a thin coat of ink. This done, I moisten it a little and roll it regularly with rollers freshly treated with color, so that the picture comes up harmoniously and strongly.
Rolling off during drying keeps the gum solution from the drawing while drying on, and keeps open the connection for rolling in.
Before going further I will explain the terms used*: To roll in is to give color or ink, and is done slowly, with tightly grasped handles and certain pressure. Rolling off is effected with loosely grasped handles, without pressure, and quickly, and is intended to draw off with the rollers any excess of color on the plate. To work out or make the rollers means to bring fresh color on it from the grinding stone, and is done with strong pressure and strong traction. The correct management of the rollers rests in the wrists. To reverse the rollers, to change the handles, means to turn the rollers around, to make the left-hand handle the right-hand one, and thus to correct irregularities in the distribution of color. After every advance and return on the stone or plate to be blackened the rollers are newly adjusted. The plate thus strengthened must be well {78} washed with clear water, to be dried, and at times even to be retouched with a brush and color dissolved in oil of turpentine.
* Color and ink are synonymous. “Burn in” and “melt in” mean the same.
(b) Blackening in with a sponge. The initiatory etching is done with gallic acid, the gum coating put on and additional gallic acid poured over; then some turpentine solution of copy color, the consistency of syrup, is rubbed over the plate until the picture is uniformly strengthened. If, as may happen in hand-drawings, the color should become massed and not attach itself smoothly, it must be washed off with turpentine and then clean color must be rubbed on.
This operation requires great delicacy. After having finished the blackening in, rinse well, dry with a sponge and thick blotting paper. Heat, so as to vaporize the last remnants of dampness, and retouch.