Unglazed porcelain bones are called tires, because the mud used for tires is fine and thick, so tires also have various names. Porcelain tires made of ordinary porcelain clay; Mud water, fine powder, slurry tire; Thick tile tire; Heavy and simple are stone tires; An iron fetus is called an iron fetus. The soil for making porcelain tires includes hemp storage soil and kaolin. thank you