Kyo-yaki 京焼 / Kiyomizu-yaki 清水焼
Both kyo- and kiyomizu-yaki are general terms, often used together or interchangeably, for stoneware or porcelain pottery produced in the ancient imperial city of Kyoto and encompass a wide variety of ceramic styles. From 794 to 1603, Kyoto was the imperial capital and attracted the most skilled artisans in the country. Even after the seat of government was moved to Edo, now Tokyo, Kyoto remained the cultural and intellectual centre of Japan. As such, it attracted Japan's most skilled artisans, who were supported by nobility as well as the purchasing power of the market. This gave Kyô-yaki special status in Japanese ceramics, and for a long time it even determined the style for the whole country. Typical Kyoto wares are decorated with colourful, hand-painted motifs using overglaze enamels: a technique that emerged in the 17th century and is still a trademark of Kyo-yaki today.
Seiji 青磁 – Celadon
Seiji, literally "green porcelain", or celadon in Europe, is a form of jade green pottery that originated in ancient China. The glaze of seji is made from an iron oxide ash reduction fired at a temperature of over 1,200°C. This results in colours ranging from blue to green, depending on the iron content and the exact firing process. The technique eventually spread to Korea, Southeast Asia and Japan, where powder blue funsei (粉青) celadon wares, made in China during the Southern Song dynasty (1127-1279), were particularly prized at the time.
Like cracks on the ice of a frozen lake as spring approaches, the fine cracks on the surface of glazed ceramics are known in Japanese as kan-nyu (貫入) and are highly prized for their aesthetic quality. The special cracked effect is caused by the different rates of expansion and contraction between the body and glaze during firing.