Note 12 — Chapter V

(p. 38.) To make the varnish, or rather etching-paste, recommended in the text, a warm-water bath is not absolutely necessary. Take any small porcelain or earthenware vessel (a small gallipot is very convenient, because the etching-paste can be kept in it for use), and set it upon a metal frame, easily made of wire, so that you can introduce a spirit lamp under it. Break up a ball, or part of a ball, of ordinary etching-ground, and throw it into the pot. Heat the pot carefully, so as just to allow the ground to melt. When it has melted, add oil of lavender (worth thirty-five cents an ounce at the druggist's), drop by drop, and keep stirring the mixture with a clean glass rod. From time to time allow a drop of the mixture to fall on a cold glass or metal plate. If, on cooling, it assumes the consistency of pomatum, the paste is finished.

As I have said before, this paste cannot be used with the India-rubber rollers recommended in Note [5]. With these rollers the regrounding must be done with the ordinary etching-ground with the aid of heat. Warm your plate so that you can just bear to touch it with the hand, and allow some of the ground to melt on a second, unused copper plate. Also warm the roller slightly. Then proceed as M. Lalanne directs in his fifty-seventh paragraph. The slight changes in the proceeding, which grow out of the differences between cold and warm ground, are self-evident.

It is hardly necessary to say that the roller can also be used for laying the first ground. But it is of no use on any but perfectly smooth, straight plates, as it cannot penetrate into hollows. When it is not available the dabber must be employed in the old manner.