Black Clay Tobikanna Mug — Kiln-Fired Japanese Pottery by SeitoenThe iron rich glaze on this mug darkens in the kiln and pools at the foot, leaving a surface that reads differently depending on how the light falls. The depth comes from the firing, not from any added decoration. Seitoen forms and firing each mug by hand in Japan, working at a pace that allows every piece to be made individually. The result is a mug that carries the marks of its making never perfectly uniform, always consistent in character. Japanese