Bone carving is creating art, tools, and other goods by carving animal bones, antlers, and horns. It can result in the ornamentation of a bone by engraving, painting or another technique, or the creation of a distinct formed object. Bone carving has been practiced by a variety of world cultures, sometimes as a cheaper, and recently a legal, substitute for ivory carving. As a material it is inferior to ivory in terms of hardness, and so the fine detail that is possible, and lacks the "lustrous" surface of ivory. The interior of bones are softer and even less capable of a fine finish, so most uses are as thin plaques, rather than sculpture in the round. But it must always have been much easier to obtain in regions without populations of elephants, walrus or other sources of ivory.