About Urushi

Urushi is the most important material in Wajima-nuri. It is a thick honey-like liquid refined from the sap of Japanese lacquer trees and is used in every stage of the production process. The extracting process from the tree is very similar to the process used to obtain sap from rubber trees but requires much more time and effort. Only 150g of sap can be collected from each mature lacquer tree over ten years old. In comparison to the world’s annual yield of diamonds which is about 30 tons, only 1.5 tons of the internationally recognized highest quality Japanese urushi can be obtained in a year. A tub of Japanese urushi costs 8,000 euros and a large proportion of this precious urushi is used to produce Wajima-nuri.

Urushi is very robust. An urushi-coated bowl can withstand the extreme temperatures of being used for hot soup every day. Its chemical resistance is also so high that even aqua regalis (nitrohydrochloric acid) which melts gold cannot erode it. Urushi has a hardness of 6 on the Mohs scale, which is the same as that of glass. Lacquerware pieces have been found that date back 7000 years. The fact that they survived shows how durable urushi is.