a method of engraving on copper, in which the lines or strokes, instead of being cut with a tool or graver, are eaten in with aquafortis.

Etching is done with more ease and expedition than engraving: it requires fewer instruments, and represents most kind of subjects better and more agreeable to nature, as landscapes, ruins, grounds, and all small, faint, looie, remote objects, buildings, &c. See ENGRAVING.

The method of etching is as follows: Chase the copperplate as directed for engraving, and furnish yourself with a piece of ground, tied up in a bit of thin silk, kept very clean, to be laid upon the plate, when both have been warmed; proper needles, to hatch with on the ground; a pencil or brush, to wipe away the bits of ground which rise after its hatching; a polisher; two or three gravers; a pair of compasses, to measure distances and draw circles; a ruler, to hatch straight lines; green wax, to make the wall round the edges of the plate, to contain the aquafortis; an oil-stone; a bottle of aquafortis; some red lead, to colour the back side of the copy; a stiff, and a hand-vice, to hold the plate over the candle. See NEEDLE, GRAVER, POLISHER, COMPASS, &c.

To make the ground, take three ounces of asphaltum, two ounces of clean rosin, half an ounce of Burgundy-pitch, three ounces of black wax, and three ounces of virgin-wax: let all these be melted in a clean earthen pipkin over a slow fire, stirring it all the time with a small stick; if it burn to the bottom, it is spoiled. After the ingredients are well melted, and it boils up, put it into a pan of fair water; and before it be quite cold, take it out, and roll it into small lumps to be kept from dust: this ground is what others call the varnish. The next thing is to clean the plate to receive the ground: take a piece of linting, roll it up as big as an egg, tie it very tight, so as to make it a rubber; and having dropped a small quantity of sweet oil, and added a little powder of rotten stone on the plate, rub it with this ball, till it will almost chew your face. Then wipe it all off with a clean rag; and after that, make it quite dry with another clean rag and a little fine whitening.

The next thing is to lay on the varnish; to do which aright you must take a hand-vice, and fix it at the middle of one part of the plate, with a piece of paper between the teeth of the hand-vice and the plate, to prevent the marks of the teeth; then laying the plate on a chaffing-dish, with a small charcoal fire in it, till the plate be so hot, that, by spitting on the back-side, the wet will fly off: rub the plate with the ground tied up in silk, till it be covered all over; and after that daub the plate with a piece of cotton wrapped up in silk, till the ground be quite smooth, keeping the plate a little warm all the time. The varnish being thus smoothed upon the plate, it must be blacked in the following manner: take a thick tallow candle that burns clear, with a short snuff; and having driven two nails into the wall, to let it rest upon, place the plate against the wall with the varnish side downward, and take care not to touch the ground with your fingers: then taking the candle, apply the flame to the varnish as close as possible, without touching the varnish with the snuff of the candle, and guide the flame all over it, till it become perfectly black. After this is done, and the plate dry, the design is traced with a needle through the varnish, and a rim or border of wax is raised round the circumference of the plate; and then the artist has a composition of common varnish and lamp-black, made very thin, wherewith he covers the parts that are not to be bitten, by means of a hair-pencil. And he is every now and then covering or uncovering this or that part of the design, as occasion may require; the conduct of the aquafortis being the principal concern, on which the effect of the print very much depends. The operator must be attentive to the ground, that it does not fail in any part, and where it does stop up the place with the above composition. The plate is defended from the aquafortis everywhere, but in the lines or hatches cut through it with the needle, through which the water eats into the copper to the depth required; remembering to keep it stirring with a feather all the while; which done, it is to be poured off again.

Single aquafortis is most commonly used; and if it be too strong, mix it with vinegar, otherwise it will make the work very hard, and sometimes break up the ground: the aquafortis having done its part, the ground ground is taken off, and the plate washed and dried: after which nothing remains for the artist, but to examine the work with his graver, to touch it up, and heighten it where the aquafortis has missed.

And, lastly, it is to be remembered, that a fresh dip of aquafortis is never given, without first washing out the plate in fair water, and drying it at the fire.