In the absence of an etching board, place the copper plate on a thick piece of brown paper larger than the plate; make two ribs of the same paper, doubled four or more times, and about an inch wide; place them at each end of the plate on the brown paper, and fasten them with sealing wax; these ribs serve as shoulders for the rest to lay on, which will prevent the hand from touching the work. Now cut the tracing paper to the size of the plate, having ruled the margin line if one is required. Place the tracing reversed; that is, with the pencil side to the plate. Fix it with pieces of soft wax round the border, leaving open the bottom to admit the transfer paper, which introduce with the chalk side next to the plate; the upper side of the paper must be kept clean, that the pencil-lines on the tracing paper may be seen. With an H H pencil, cat sharp and short, go over all the lines of the tracing with rather an upright hand and a strong pressure; the upper side of the tracing paper will show whether all the lines have been traced; look sideways at the work, and the black,lead murks will be perceptible. Before advancing far Id the transfer, lift up the bottom of the tracing to ascertain if the lines are of sufficient strength; if not, apply more red chalk to the transfer paper.
When the transfer it nearly completed, do not take off the whole of the paper, but let the top part remain fixed. Then lift up the tracing, and if any part of it has been neglected, it can again be filed down, and the omission rectified.
Commence with a fine-pointed needle, No. 1, and go carefully over the outline, not making much impression on the copper, but sufficient to remove the ground; with the same point go over all the lighter parts, increasing the pressure, so as to make a slight indentation on the plate. No. 2 point mallow be used to go over the lighter shade, with an increased weight of hand. No. 2 point will answer for the darker shades making the lines nearer together and increasing the pressure. Interline parts that require extra colour with No. 1 point; the etching may he worked at for a considerable time by interlining and dotting. If there are any marks to expunge, dip a pointed camel-hair pencil into the turpentine bottle, and with its point work up some of the ground on the margin of the plate, and therewith slop out the objectionable marks. When set, it will resist the aquafortis.
In cold weather the wax will be too hard to roll out with the hand; in that case it must be placed in moderately til it becomes pliable; then pull and roll it out, Fig. 27, to about the thickness of a small walking-stick; slightly grease the point of the thumb and two forefingers with mutton fat; press the roll of wax flat, and place it on the border of the plate with the edge to the varnish, taking great care that the bordering wax does not go off the Tarnish, At the parts intended to be the darkest corner of the plate, pinch out the wax border, that the height of the wait may be increased at that corner where the spout is to be formed with the was to prevent spilling the aquafortis in pour ing it off.
Lay the plate flat on a piece of canvas larger than the plate, as a protection from any splashings that may be made. Place the spout of the plate in front for the convenience of pouring off. Pour a little water over the plate to tee if there are any leaks in your border; it' there are any, pour off the water; let the plate dry, particularly in the defective part; then press down the outer edge of the wax with a piece of wood. Leaks can also be found without using water by holding the plate upto the light and looking at the edge, when the smallest pin-hole will be immediately detected. Have two or three small wedges, to be used for tilting the plate should the acid not layeren. When the border is sound, pour off the water; then cover the surface of the plate with the aquafortis from No. 2 bottle. If, in the course of half a minute, the etching on the plate should assume a light-grey coating, the mixture is good; but if it should throw up bubbles, it is over strong, and more water must be added but not on the plate. The mixture must be placed in the jug, then in the bottle, and afterwards returned to the plate. Should the lines on the plate remain as bright copper after the acid has been on half a minute, it is not strong enough, and some aquafortis out of bottle No. 3 must be added.
When the mixture on the lines does not produce a foam, but the plate continues of a grey, frosty appearance, the process is going on well. The power of biting-in correctly depends on the experience in using the acid. With a soft camel-hair pencil, lightly remove the frosty appearance, taking care that the quill does not touch the ground. Should any part of the ground break up by the lines becoming united, pour off the acid carefully into the jug.
Lay the plate again on the flat, and cover it with water from the other jug, moving it gently with the camel hair pencil, which place at once in a water jug when taken from the acid, or it will soon be destroyed. Throw away the wash water from the plate. When the first biting is completed set the plate up endways to dry, Fig. 28.
When the plate is perfectly dry, take off with a blunt point covered with silk and dipped in turps a spot of ground in the lighter part to ascertain if the acid has made sufficient indentation. If it has, work up the stopping-out varnish with a camel-hair pencil, and with it cover all the parts intended to remain light; elevate the rest, Fig. 29, so as not to press the border wax. When the stopping out varnish is dry, which may be ascertained by placing the finger on it (if it does not stick, it is dry), put on the same aquafortis (bottle No. 2),and let it remain until you observe the ground giving way; then pour off the acid, and wash well as before. Put the plate to drain. Should it be required, more biting may be done; the process is the same.