There are many steps in producing these bowls & spoons, from colouring the porcelain body, creating the forms, refining the pieces as they dry, first firing which turns them from clay to ceramic, glazing & re-firing to a high temperature of 1265 degrees to create a strong, non porous form, which is fully functional if so required. Finally I sand the exterior to give a tactile smooth surface making them a pleasure to handle. I would recommend hand washing.