Put the soft clay work into cold water (preferably pure water, as tap water contains calcium carbonate, which can cause scaling on the surface and affect its appearance), heat it over warm heat until it boils, and keep it in this state for 10-20 minutes (depending on the size of the work). After turning off the heat, remove it with water or wait for the water temperature to cool naturally, Then remove the work (note: During the entire shaping process, gentle fire must be used, and the clay must undergo a slow heating or cooling process. A large fire can cause the item to crack due to a large temperature difference between the inside and outside). If the hardness of the first shaping is not ideal, it can be repeated again or a few times until satisfactory results are achieved. (However, be sure to wait for complete cooling before putting it into cold water for secondary shaping!)