<sod>A caustic, toxic [[Plant sap|sap]], called [[urushiol]], is tapped from the trunk of the Chinese lacquer tree to produce lacquer. This is done by cutting 5 to 10 horizontal lines on the trunk of a 10-year-old tree, and then collecting the greyish yellow sap that exudes. The sap is then filtered, heat-treated, or coloured before applying onto a base material that is to be lacquered. Curing the applied sap requires "drying" it in a warm, humid chamber or closet for 12 to 24 hours where the urushiol [[polymerize]]s to form a clear, hard, and waterproof surface. In its liquid state, urushiol can cause extreme rashes, even from vapours.  Once hardened, reactions are possible but less common.<eod>
<sod>A caustic, toxic [[Plant sap|sap]], containing [[urushiol]], is tapped from the trunk of the Chinese lacquer tree to produce lacquer. This is done by cutting 5 to 10 horizontal lines on the trunk of a 10-year-old tree, and then collecting the greyish yellow sap that exudes. The sap is then filtered, heat-treated, or coloured before applying onto a base material that is to be lacquered. Curing the applied sap requires "drying" it in a warm, humid chamber or closet for 12 to 24 hours where the urushiol [[polymerize]]s to form a clear, hard, and waterproof surface. In its liquid state, urushiol can cause extreme rashes, even from vapours.  Once hardened, reactions are possible but less common.<eod>