The Process of Oil-Gilding.
Sometimes no burnishing at all is required, while a degree of durability which cannot be conveniently obtained with burnish-gilding is desired. In this case the moulding is gilt in oil gold, by a process differing in many respects from that which we have mentioned.
For oil-gilding a ground of whiting and size is required, as in burnish-gilding, but not in so great quantity. After the application of a few coats of whiting and size, the moulding is smoothed in the manner before described; and in some cases a few coats of burnish gold size are applied, but not always. The next process is to wash the moulding with two or three coatings of strong size, by which it acquires a gloss somewhat similar to that produced by varnish, and which has the effect of preventing the absorption of the substance next employed.
The moulding is now ready to receive the oil gold size, which is an exceedingly smooth mixture of ochre and oil. This is laid on in a stratum as thin and smooth as possible; and after being set aside for some hours, it acquires a peculiar degree of clamminess between wet and dry; when it is ready to receive the coating of gold. The gold is blown into the cushion, spread out, cut into slips, taken up by the tip, and applied to the work, in the same manner as in burnish-gilding; but the moulding is not wetted with water, the partially dry oil gold size serving that purpose. The gold is, in this case, pressed down into the hollows and crevices of the moulding, by means of a piece of cotton wool; and when the whole is gilt, a soft brush is lightly applied, by which the gold is worked into small depressions, which it would not otherwise have reached, and the superfluous gold is rubbed off. The gold is now left as it is, or is washed with transparent size, or receives a coat of varnish. In either case it becomes in a short time so far hardened as to be susceptible of washing without being rubbed off.