The plant Toxicodendron vernicifluum (previously known as Rhus vernicifera), also called lacquer tree, a member of the sumac family (Anacardiaceae). It is a native of China, but has long been cultivated in Japan. When the bark is cut, it exudes a milky juice which darkens and thickens on exposure. This is the lacquer long used in China and Japan. When properly applied, the thin transparent film becomes a varnish of extreme hardness. Lacquer is a remarkably protective coating as it is not altered by acids, alkalies, alcohol, or heat up to 160°F (71°C). Nut galls, iron in solution, and gold or other metals are mixed with the lacquer before drying to make the various kinds of lacquers. The process of lacquering is technical and tedious, sometimes requiring 300–400 coats and several years to complete the finish of one item.