Three Key Styles: Jet-Black Seto-Guro Ware (Late 16th Century)
During the late sixteenth century, three styles became synonymous with Mino ware: Seto-guro, Kizeto, and Shino. The first of these to appear was Seto-guro (Seto black) ware, characterized by a deep-black glaze used predominantly on tea bowls.
Seto-guro is produced using a high-iron glaze. Pieces are pulled out of the kiln while still red hot, then rapidly cooled by plunging them in water, which gives them a glossy finish. Alternatively, they can be left to cool more slowly in the air to produce a more matte finish. Black glazes existed in Mino prior to the creation of Seto-guro, but producing a deep-black color was not possible until the introduction of kilns capable of reaching firing temperatures of 1200° Celsius, such as the anagama and ōgama.
Early examples of Seto-guro tea bowls are slightly rounded near the base, as seen in the bowl on the right. Later pieces have a distinctive cylindrical style with a low base, as seen on the left. Later still, the cylindrical style evolved into another subset of Mino ware called Oribe-guro (Oribe black), which combines the deep-black glaze of Seto-guro ware with the dramatic asymmetry of Oribe ware.