A natural product composed of hydrated sodium borate. Borax is produced by the evaporation of water in shallow lakes. Borax was used by the Egyptians for mummification and by the Romans for glassmaking. In the 9th century, it was used as a flux for soldering gold in Arabia and by the 10th century, borax was being used in ceramic glazes in northern China. By the 13th century, tincal (borax) was regularly imported from Tibet to Europe for use in Venetian glass. In pictorial techniques, it traditionally found use as an anti-decayer for animal glues and egg tempera. It is also present in recipes for the preparation of a paint for tempera and watercolor (water, borax and shellac). The white powder is now mined from deposits in India, Russia, Persia and California. Borax was one of the inorganic additives used for stucco marble preparation according to literature. Borax was especially used for stucco or special gypsum-containing cements. Synonyms: sodium borate decahydrate; sodium diborate; tincal; tincalconite; tincar; hydrated sodium boration; sodium tetraborate; rasorite; Sporax®. Wittenburg (1999); Museum of Fine Arts, Boston (2000). [J. Cassar, R. de Angelis]