The whole difference is this: if a wood block has a line cut in the surface and the whole face is inked with a roller, the line will print white and the rest of the block black. If the etching plate is inked and cleaned off, as is always done, it will print white; if a line is cut in it, the ink will remain in that and produce a black line. Of course they must be printed in appropriate presses.
In its broadest sense an etching may be produced in any one of a number of ways, by the artist, on a metal plate which may be printed from.
It is never a process or mechanical engraving, and never was and never will be, and the attempt to palm off mechanical blocks or plates is a swindle and a humbug.
Etchings are produced in the following manner; at least this is the best and simplest method.
A plate of highly polished copper, zinc, or even steel, iron, or aluminium is obtained from the makers, William Longman, of Johnson’s Court, Fleet Street, or from Messrs. Hughes & Kimber, West Harding Street, Fetter Lane, or Messrs. Roberson, 99, Long Acre. Copper, however, is the best and almost universally used. This should be carefully cleaned with a soft rag and whiting; then it should be gripped by a vice with a wooden handle, in one corner, care being taken to put a piece of soft paper between the vice and the plate to keep the teeth of the former from scratching it; heated, either upon an iron frame with a spirit or Bunsen lamp under it, or over the gas, until, if you take a ball of etching ground and touch the plate with it, the ground melts. This ground is made of resin, wax, and gum; the best is made by Sellers in England and Cadart in France. All these materials can be bought of Roberson or Hughes & Kimber. Touch the hot plate in several places with the ground. It should melt at once; then take an American etching roller (which I think you can only obtain at Roberson’s) and go over the plate rapidly with it in every direction, until the little masses of melted ground have been spread evenly and thinly in a film all over it. With a little practice you should be able to do this in a couple of minutes, and you can lay in this way (which is unknown virtually in England) a thinner, harder, more even and very much better ground, with less trouble, than in any other. Heat the plate again a little more, and take a bundle of wax tapers twisted together by heating them, light them and pass them under the face of the plate held, varnished side downwards, by the vice; do not touch the plate with the taper, or the varnish, being still melted, will come off, but go rapidly back and forward, allowing the flame only to touch the surface. In a few minutes the varnish will have been completely blackened by the smoke. Next, take a bottle of stopping-out varnish (which you may as well buy; don’t bother to make it) and cover the back and edges of the plate. If this is done while the plate is hot, it dries very fast, and as soon as the plate is cool it is ready to work on.
This is the first stage. The waxy ground is put on to protect the plate from the acid with which it is to be bitten, and it must be so well made and well put on, that one can draw through it, without tearing it up and without any resistance; also it must adhere firmly to the plate, where it is not drawn through, and must resist the acid perfectly in the untouched parts. The smoking is done to enable you to see your lines in the copper, light on dark; this is rather curious at first, but you will get used to it. The stopping-out varnish is also to protect the plate, and is only a cheaper sort of ground dissolved in oil of lavender or ether. When the plate is cool, it should be of a brilliant uniform black, and if there are any dull, smoky-looking places on it, the ground is burnt. Here the ground may be rubbed off, or will show cracks, if you touch it, in these places, and the varnish should be cleaned off the face with turpentine, the plate carefully dried and regrounded. Otherwise the varnish will either crack while you are drawing on it, or come off in the bath of acid, and your work will be spoiled.
You draw upon the varnished plate with needles or points; any steel points will do, from a knitting-needle to the best big point you can get. The small needles invented by Mr. Whistler I find the best; but this is a personal liking. They are of all shapes and sizes. You may commence and draw in your entire subject, only remembering that you must leave your foreground lines further apart than those in the distance.
You may make your drawing either with the same needle, all over, or with needles of different sizes; for though one half of the art is in the drawing, the other half, and the really characteristic half, is in the biting. There is very little to be said about the drawing, save that you must draw just as well as ever you can; you will find out almost immediately that you have the most responsive tool in your fingers, and that you can work with it in any direction. Do not bother, if you use the same needle, because the drawing looks flat, and the lines are of the same width; the biting will fix all that. Draw away; if you are afraid to tackle the copper straight away with a point, paint your design on it, with a little Chinese white, or, if you have a pencil drawing of the subject, you may make a tracing from it, and go over that, transferring it to the plate; or you may turn the drawing face down and run it through a copper plate press; the drawing will come off on the varnished surface in reverse, and if you are doing a portrait of a place you must otherwise reverse it yourself. If you wish to sketch from nature in reverse, put up a mirror on an easel, and turn your back to the subject, drawing from the picture in the mirror, for, you must remember, that any subject drawn, as you see it, on a copper plate, or even a wood-block, prints in reverse.
Next, to bite or etch the drawing into the copper plate, take equal parts of nitric acid and water and mix them in a glass-stoppered bottle, some hours before you wish to use the mixture, for there is enough heat produced by the chemical action to melt the ground if it is used at once.
Or have a quantity of what is known as Dutch mordant made; this is composed of—