Outlines should not be drawn upon the zinc in the first instance, but upon a strip of paper (which may be several sheets pasted together at the edges), wider than the scroll, so that it may be folded firmly over it, and the letters traced, as already explained (page 7). Any thin common paper answers for this purpose: tissue would be too thin. Tracing is recommended, because the process of erasing pencil-marks, although easily effected with spirits of turpentine, is apt to leave a smear, and spoils the smooth clearness of the foundation-colour.
Chalk-tracing.
On a dark-coloured ground the following method is pursued. Draw the text, as usual, on common cartridge-paper (3 or 4 inches wider than the zinc, so that the edges may be turned down firmly over it): with pointed scissors cut the letters out and put them aside, as they are not required: lay the remaining paper-groundwork on the zinc, and with red or white tailor's pipe-clay trace carefully round the outlines of the spaces which form the letters. When all are traced, remove the paper, and with a handkerchief brush away, very lightly, the superfluous chalk.
Dry Foundation-Colours.
Special care must be taken not to begin the lettering until the foundation-colour be perfectly hardened, otherwise the pressure of the pencil will make indented lines which cannot be removed, should correction be necessary. In cold, damp weather, the paint dries and hardens very slowly, so that the foundations should be prepared at least a week before they are required for illuminating.
To paint the Letters.
In proceeding to paint the letters, squeeze out a small quantity of the colour on to the wooden palette, and with the flexible palette-knife mix it with a little of the pale drying oil, and a very little spirits of turpentine. The latter can be dispensed with, if the smell of it be found injurious; otherwise it contributes to brighten the colours, and makes them dry more quickly. In painting keep the brush full, laying on the colour in long steady sweeps, not in short, hasty touches, which would leave irregularities of surface.
Corrections.
Spirits of turpentine, used alone, will serve to remove the colour, if correction be necessary; but care must be taken not to apply enough to remove the foundation-colour at the same time. If a wrong colour be accidentally applied, another can be painted over it, but, of course, this should be avoided if possible.
Gold-leaf.