Substitutes for ivory are bone, xylonite, and a French celluloid. The two latter pro (ructions may be obtained in sheets from 1/16 in. to 2 in. in thickness, and in blocks to order. They are subject to considerable shrinkage, but can be cut, carved, pressed, moulded, and polished, and are highly inflammable. Information on working celluloid is given on p. 98. When bone is intended to take the place of ivory, only the best cuts are used, and a higher finish is given to the manufactured article.