Nurikomi, Wazuku Iron Kettles: Boiling Hot Water for Tea

Once the outer surface is created, then intricate designs are added. The photograph shows sand being formed to the inside of the mold. When iron is poured into the mold, the raised areas of sand create concave patterns on the surface, in this case resulting in a design of mountains. This stage is called nurikomi and was used in kettle production even as early as the Muromachi period (1336–1573).