Goldleaf
fine gold beaten into thin leaves. A small percentage of silver and copper is added to the gold for beating, about 1½ per cent. of alloy. The ingot is rolled into a ribbon by repeated passage between rollers, and this ribbon has a thickness of 1-800 of an inch, a surface of 500 square inches to an ounce of gold. It is then cut into pieces of about 1 inch square, placed between pieces of goldbeater's skin 4 inches square, and beaten with a ponderous hammer on a smooth marble slab till the gold has thinned and expanded to the size of the vellum. Each piece of gold is then again divided into 4, placed between pieces of goldbeater's skin as before, and again beaten till it expands to the size of the skin. A third and a fourth beating follow. An ounce of gold in the form of a cube, cube, 54 lines in length, breadth, and thickness, can be so extended by the goldbeaters as to cover a surface of more than 1,466½ square feet.
Wood, plaster, papier-maché, and many other substances may be gilded by covering them with goldleaf stuck on with a kind of sizing or glue. The gold leaf is not put on the wood, plaster, etc., itself, but on a mixture of whiting and glue called size.
In gilding picture frames, for example, the wood is painted glue called size. In gilding picture with four or five coats of size put on hot.
This is carefully smoothed, when dry, with pumice stone and fine sandpaper, and another size, made of clay, red chalk, black lead, suet, etc., is then put on.
This, which is called gold size, is the GOLDONI groundwork for the gold leaf. In gilding on metals or surfaces to be much in the open air an oil size is used.