The gold is cast into ingots weighing about two ounces each, and measuring about three-quarters of an inch broad. These ingots are passed between steel rollers till they form long ribbons of such thinness that a square inch will weigh six and one-half grains. Each one of these is now cut into 150 pieces, each of which is beaten on an anvil till it is about an inch square. These 150 plates are interlaid with pieces of fine vellum about four inches square, and beaten till the gold is extended nearly to the size of the vellum leaves. Each leaf is then divided into four, interlaid with goldbeater's skin, and beaten out to the dimensions of the skin. Another similar division and beating finishes the operation, after which the leaves are placed in paper books ready for use. The leaves are about three and a quarter inches square and are produced in ten different shades of color, according as the gold was alloyed with much or little copper or silver.