The apparatus consists of copper plates, etching needles, hand-rest, etching-ground, dabber, oil-rubber, rotten-stone, smoking taper, engraver's shade, bordering wax, stopping-out varnish, tracing-paper, and aquafortis.
The ground is composed of equal parts of asphaltum, Burgundy-pitch, and beeswax; place them in an earthen pipkin in an oven, and melt. The mass must be kept stirred until well incorporated. Pour the mixture into a basin of cold water, and, when nearly cold, press and roll with the hand until all the water is discharged, then make into a ball. Procure a piece of worn silk, without holes; double it; place the ball therein, and tie up the ends with packthread, taking care that the double silk reaches well and tightly over the ball; cut off the surplus silk, and let the knot remain for a hand-hold.
Take a piece of silk, twice the size of that for the ground ball; double it; place in it a ball of coarse wool well picked out, about the size of a small apple; tie it up in the same way as the ball for the ground, and it is ready for use.
An oil-rubber is made from a strip of woollen cloth, about 2 inches wide, rolled up tightly, and bound over with packthread or thin tape. With a sharp knife cut off one end, avoiding the string, so that the surface may be quite flat. This is used for taking out stains, or polishing the plate, as in Fig. 20.
Take a piece of fine flannel, rather less than the silk which covers the etching-ground ball; double it; place on it a small quantity of rotten-stone, in powder, which tie up in a bag. A small portion of fine whiting in the lump should be also kept at hand.
For small plates, procure a wax taper; uncoil it by degrees before the fire until it is all equally pliant; double it up in about six lengths; give it one twist while warm, and turn it a few times before the fire, that the pieces of taper may adhere to each other; melt the wax at one end, so that the wick is exposed; see that all the cotton ends will light freely; care should be taken to extinguish the cotton, or it will revive with the least draught, and may become dangerous. For large plates it is preferable to use an ordinary oil lamp mounted on gimbals; this obviates the inconvenience occasioned by the dripping of the tapers.
3 oz. rosin, 2 oz. beeswax, and such a quantity of sweet oil as will soften the mixture to fancy. Procure an earthen pipkin; place in the bottom 1/2 oz. or more of sweet oil; add the rosin and beeswax, broken in small pieces; when melted, work the ingredients well together with a stick until thoroughly incorporated; then pour into a basin of cold water; as it gets cold, work it well with the hands by pulling out into lengths and doubling it together again; the more it is worked the better it will be for use. Should it turn out brittle, return it broken to the pipkin, and add more oil; work it well together as before, pour it into water, and work it again with the hands.
Bend a piece of wire into a half-circle; bind it together with waxed string; lay it on tissue paper; cut away all but 1/2 inch round the wire: cover that 1/2 inch with paste, and turn it over the wire; when dry the shade is complete. Fasten a light string to the centre of the half-circle, and suspend it from the window-latch when in use. This shade must be placed in a forward position, sloping before the plate, and the white light it produces will enable the engraver to see the lines made by the etching needle. An equally effective shade may be made by covering a light square wire frame with tissue paper, and supporting it with two struts. This frame can be made to rest at any angle, upon the table immediately in front of the work.
Any flat and thin piece of wood will answer the purpose, which is to keep the hand clear of the plate whilst at work. A good hand-rest may be made of a thin board raised above the work upon side pieces of such a height as to allow the plate to be freely moved underneath the board. The front edge of the board may be faced with a strip of steel planed true, when it serves as a straight-edge. This arrangement will be found extremely handy.
Break small pieces of rosin into a phial; pour over spirits of turpentine to about twice the height of the rosin. Place the bottle in a small saucepan of water on the hob, near enough to the fire to make and keep the water hot; place a cork lightly in the mouth of the bottle, as the mixture will require to be shaken occasionally. Pour a small portion of this mixture into a small pot, with a little lampblack added to give it a colour, and well mixed. This last is necessary to prevent lumps; it may be done by working the mixture well together with the camel-hair pencil. This is a good stopping-out varnish. With this varnish go over the border or margin of your plate; do this when about to put it away, and the varnish will become hard by being left a night to set. When biting-in again, go over the margin, using the same brush and mixture. It can always be worked up by adding a little turpentine. When it is set so hard that the finger may be placed on it without sticking, it is time to make up the wall or border of wax to hold the aquafortis.
Procure three half-pint bottles with glass stoppers, and two pint earthen jugs with spouts. Place 1/2 lb. of nitric acid in bottle No. 1. Pour into bottle No. 2 rather less than the fourth of the nitric acid; fill the bottle 3/4 full of water; slowly pass it into one of your pint jugs, and back again to the bottle, to mix it well. In bottle No. 3 put one-half of the remaining nitric acid; water it as before; see that the nitric acid in bottle No 1 is well stoppered, and cover it with a piece of old glove.