I received this from a friend, but I haven't used it at all. What is "Kanyu" (Crackle)? Kanyu refers to the crack patterns in the glaze that occur during cooling after firing, due to the difference in shrinkage rates between the glaze and the ceramic body. It is different from cracks or damage that occur when something breaks. In general, ceramic ware is glazed on the ceramic body and then fired at a high temperature, ranging from 1200 to 1300 degrees Celsius, depending on the type of glaze. During firing, the glaze melts and forms a glass-like layer that covers the ceramic. After firing, the temperature of the ceramic itself decreases, but the shrinkage rate differs between the ceramic body and the glaze. If this difference is significant, the glaze will crack and solidify. This is called Kanyu (crackle). It is said that Kanyu can be heard forming with a "pinging" sound during cooling, and that sound is very beautiful.