Small, flat subjects are best to begin with, such as hinge-plates, panels, escutcheons, or tablets. For a drawer panel, Fig. 2 shows an attractive and simple design that may be drawn on the metal with pen and ink. If the ink creeps, the surface of the metal may be roughened slightly with fine emery cloth.
With the asphaltum varnish the design is then filled in so it will appear as shown in Fig. 3 and allowed to dry, when, as a precautionary measure, another coat should be given over the blackened surface, to avoid the possibility of the acid biting through the thin places, or where the varnish has missed the metal. The back and edge of the metal is coated also, to prevent the acid from eating into it.
All the surfaces of the metal not covered with the varnish will be eaten or etched away and left with a granular surface resembling fine sand-paper, while the painted or protected parts will be left intact and with a smooth surface like the original face of the plate, as shown in Fig. 4.
The Technique of the Process
With an old woollen cloth dipped in turpentine, the surface of the plate may be rubbed, after first washing off the acid. The black removed from the ornament will tint the granulated surface of the background and lend relief to the bright surface of the ornament.
Almost any objects in metal, such as door-hinges, knobs, fireplace hoods, name-plates, vases, candlesticks, panels, and tablets, can be decorated by this process, and if artistically done the results will be very effective.
Sheet brass and copper may be purchased at large hardware stores or supply houses for thirty cents a pound, and the sheets or panels can be cut there with the shears to the exact size required. For the average work, metal not more than one-sixteenth of an inch thick will be found easy to handle; but for large panels or name-plate, pieces about one-eighth of an inch thick are preferable.
If the design shown in Figs. 2, 3, and 4 is too elaborate for the beginners, some simple outline may be drawn, perhaps a flower design, copied from some piece of embroidery work, or a figure design from a wall-paper, carpet, or dress-goods pattern. The metal should be left to dry for at least an hour after being painted with the varnish before it is placed in the acid bath.
The etching is done by placing the plate, face up, on the bottom of the tray and covering it with acid. The ground-work or unpainted portions of the metal may be bitten to any depth, but it is not desirable to cut away too much, as it weakens the plate and cuts under the ornament, unless it is carefully stopped out all around the edges of the design; and that is too much of an undertaking for the young craftsman, since it requires a great deal of time and careful work.
