techniques involve chiseling and bonding plate glass with polymer silicates and UV light. Pottery Pottery is one of the oldest materials for sculpture, as well as clay being the medium in which many sculptures cast in metal are originally modelled for casting. Sculptors often build small preliminary works called maquettes of ephemeral materials such as plaster of Paris, wax, unfired clay, or plasticine. Many cultures have produced pottery which combines a function as a vessel with a sculptural form, and small figurines have often been as popular as they are in modern Western culture. Stamps and moulds were used by most ancient civilizations, from ancient Rome and Mesopotamia to China. Wood carving Wood carving has been extremely widely practiced, but survives much less well than the other main materials, being vulnerable to decay, insect damage, and fire. It therefore forms an important hidden element in the art history of many cultures. Outdoor wood sculpture does not last long in most parts of the world, so that we have little idea how the totem pole tradition developed. Many of the most important sculptures of China and Japan in particular are in wood, and the great majority of African sculpture and that of Oceania and other regions. Wood is light, so suitable for masks and other sculpture intended to be carried, and can take very fine detail. It is also much easier to work than stone. It has been very often painted after carving, but the paint wears less well than the wood, and is often missing in surviving pieces. Painted wood is often technically described as "wood and polychrome". Typically a layer of gesso or plaster is applied to the wood, and then the paint is applied to that. Social status of sculptors Worldwide, sculptors have usually been tradesmen whose work is unsigned; in some traditions, for example China, where sculpture did not share the prestige of literati painting, this has affected the status of sculpture itself. Even in ancient Greece, where sculptors such as Phidias became famous, they appear to have retained much the same social status as other artisans, and perhaps not much greater financial rewards, although some signed their works. In the Middle Ages artists such as the 12th-century Gislebertus sometimes signed their work, and were sought after by different cities, especially from the Trecento onwards in Italy, with figures such as Arnolfo di Cambio, and Nicola Pisano