Urushi sap polymerizes oxidatively via ortho-quinone: it forms a hardened colored film when exposed to air. This film is very stable against almost all kinds of chemicals, but is not resistant towards the harmful effects of light. Absorption of light causes scission of the polymerized sap to form smaller molecules, which may volatilize, resulting in the fading of the film. Some extractives from Japanese cedar like sugiresinol and hydroxy sugiresinol oxidatively polymerize to form a colored polymer like urushi, but their coloring increases when exposed to light. A combination of urushi sap and these cedar extractives can be used for conservation of light-exposed wooden objects. -- AATA