Black Raku tea bowls are fired individually in a closed saggar standing on legs inside a small, charcoal-fuelled kiln whose design has remained essentially unchanged since the late 16th century. Bellows are used to raise the temperature to between 1200 and 1250 degrees centigrade. The spyhole in the domed lid permits observation of the melting glaze. Once the glaze has matured, which takes in the order of 30 minutes, the bowl is removed from the saggar with a pair of long-handled wrought iron tongs like these.