Yokkaichi Banko Yaki is produced in Yokkaichi City, Mie Prefecture, known for everyday items, art pieces, and especially its signature shidei (purple clay) teapots and donabe (earthenware cooking pots). Banko ware accounts for 80-90% of all donabe produced in Japan, a testament to its exceptional heat resistance. This quality comes from mixing the potter's clay with around 40% petalite, a lithium mineral that allows it to withstand direct heat—a patented technique unique to Yokkaichi Banko Yaki. Shidei teapots are fired using clay rich in iron, which reacts with flames to produce a peculiar, attractive color whose shine increases with use.