The etching-trough is a square, well-pitched box whose bottom is depressed toward the middle, that the etching fluid may gather there and run through a hole into a receptacle, so that it can be poured over the stone again. The trough must be large enough to accommodate the stones easily. These must not, however, touch the bottom, but must rest on little pieces of wood or cross-pieces.
Besides the ordinary rulers, a large, broad one is required, about three to four feet long, five inches wide, and so shaped that on one side it is one-half inch thick, on the other only two lines thick. On this latter side a strip of pear wood must be glued and very truly planed off. Thus it can be used for drawing lines, although the real purpose of this ruler is only for supporting the hands when working on stone, that they may not touch the prepared surface.
If the work-table is made with high pieces at the ends so that the ruler can rest on them without touching the stone, no ruler supports are required. Otherwise one must have these two pieces, a little higher than the stone, so that the ruler may rest on them.
A specially made work-table has another advantage. In the middle there can be a turntable on which the stone rests, so that it can be moved easily into any position, something that is very difficult with large stones without this arrangement.
Music-writing pens are brass or silver tubes which have the shape of musical notes underneath, and which take up such a quantity of chemical ink that one can make about twenty notes without re-dipping. That they shall not take up too much ink, a fine wire is fastened in the centre. These instruments must be very exactly ground and their use demands some skill if the notes are to be uniform.
Instead of this instrument a piece of wood may be used, but this must be inked anew for each note. To avoid dipping too deep, it is best to spread some ink on a little stone and ink the instrument from this. It must be wetted in the beginning, that the ink may be sucked up about three lines high. After that the ink on the stone need merely be touched with it, and this makes the work very uniform. Beginners find this easy to use. But one works more swiftly with the other.
Of the rastrums, there is nothing to say except that they are of steel and very even at the ends so that they touch the stone in all places. They serve to draw the five lines for music. For making the broad strokes for notes, one can use coarse drawing-pens, or coarsely cut steel pens; but the best are those adjustable drawing-pens that are made from three blades.
The brush for spatter-work, the wiping-machine, and the dauber will be described in the description of the styles of work for which they are used.
Ink-rollers and balls are for laying on the printing-color. The latter are made from soft leather, stuffed with horsehair, like the ordinary book-printer's balls. The former are wooden cylinders with thin handles, of any requisite length and about four to five inches thick. They are wound with two or three thicknesses of woolen cloth and then covered very firmly and evenly with leather. Usually there is used sheep's leather from which the grease has not been entirely removed. Calfskin, worked white, is good and more durable. Dogskin is considered best. Some printers use soft red calfskin, turning the inner side out. The leather must not be stitched with linen but with silk thread, because linen does not take the ink as well as leather and silk do. The leather must be dampened when being drawn over the cylinder.
A fair stock of these rollers is required, because they are liable to become water-soaked during use, when they lose much elasticity and fail to give good service, so that dry ones must be on hand.