GOLD Plates for Enamelling are generally made of ducat gold, whose fineness is from 23\frac{1}{2} to 23\frac{1}{4} carats; and the finest gold is the best for this purpose, unless where some parts of the gold are left bare and unpolished, as in watch-cases, snuff-boxes, &c. for which purpose a mixture of alloy is necessary, and silver is preferred to copper, because the latter disposes the plates to tarnish and turn green. See ENAMELLING.