Zero Japan products are made from the finest porcelain quality clay. A lot of manual work is required, from shaping to glazing the products. The entire process, including firing in the kiln, takes several days. The bisque firing or first firing at a lower temperature is used to dry the clay, after which the glaze is applied by hand. The second firing at a very high temperature, which lasts about 18 hours, is used to make the product waterproof and to glaze the glaze. The right temperature ensures a brilliantly shiny glaze and a beautiful color. Japanese designer Koji Inoue designed Zero Japan's products with the following three concepts in mind: "highly functional", "beautiful to touch" and "a delight for the eye". All teapots are equipped with a strainer for loose tea. The spout is design.