urushi

Refers to a natural resinous exudation made from the sap of the tree Rhus verniciflua or other trees of the Anacardiaciae family found in the Far East, used in Japanese and, to a lesser extent, Chinese lacquering and also in Japanese prints called "urushi-e." Urushi hardens by oxidative polymerization when thin coatings are exposed to high humidities at moderate temperatures. The term is sometimes used to refer to objects made from this lacquer and the technique of doing the lacquering.