Large Storage Jar (Ōtsubo)

To smooth this large, bulbous vessel with its wide shoulder and flared neck, the potter used a paddle carved with parallel grooves, leaving fine-lined marks across the exterior. The gray tone of the body was achieved by introducing an excess of fuel at the end of the firing to induce a smoky atmosphere, depositing carbon onto the surfaces. This technique also seals the pores of the clay, making the vessel ideal for holding liquids. The temperature in the wood-fired kiln was high enough to melt the wood ash into a thin, greenish-brown natural glaze. This high-temperature firing method was introduced to Japan from the Korean Peninsula in the early fifth century. Before this major technological innovation of stoneware, Japanese potters produced only low-fired, porous earthenware.