The method of making a cut differs somewhat, depending on the locality. Generally in Japan, five to ten horizontal cuts are made in parallel and the sap oozing out is scrapped and collected. The higher the urushiol content, the great is the hardness after the lacquer is applied. As against 50 percent urushiol and 20 percent gum in Chinese, Vietnamese and Thai lacquer, Japanese lacquer contains from 70 to 80 percent urushiol and 7 percent gum. The lacquer juice collected from the tree is called raw material lacquer or crude lacquer.
Crude lacquer is used as the priming for lacquerware.
Depending on use, Kurome lacquer is mixed with pigment or oil to produce colored glossy lacquer for the top layer of lacquerware. Drying of lacquer becomes slow or fast, depending on not only the quality but also heat and humidity. When left there for a lengthy period of time, the lacquer gradually hardens. In case coloring material is not added, a transparent and beautiful brownish color results. This quality of lacquer to harden rapidly in high temperature is utilized for applying it on metalware and ceramics.