What is this amazing Tenmoku art?
Tenmoku or Jian Zhan, a cup adored by the Chinese emperor and Japanese monks, not to mention the great daimyo at the time of the Japanese warriors. The temoku cup has fascinated generations and generations of lovers of tea, ceramics and Asian culture. How is this mysterious cup able to attract so much attention and passion? We will discover its history and reveal its true nature together in this article.
History
Tenmoku is named after the temple on Tianmu Mountain (天目, Mandarin: tiān mù; Japanese: ten moku; English: Heaven's Eye) in China, where enameled iron bowls were used for tea. The style became very popular during the Song Dynasty (960–1279). In Chinese, it is called Jian Zhan (建盏), meaning “Jian (tea) bowls”.
According to the chronicles of 1406, Emperor Yongle (1360–1424) of the Ming Dynasty sent ten Jian bowls to Shogun Ashikaga Yoshimitsu (1358–1408), who reigned during the Muromachi period. A number of Japanese monks who visited monasteries in China also brought pieces home. As they became popular for tea ceremonies, more and more pieces were imported from China, where they became highly prized items. Three of these Southern Song Dynasty vessels are so highly prized that they have been listed by the government as Japan's national treasures.
Features
It is composed of feldspar, limestone and iron oxide. The faster a piece is cooled, the blacker the glaze will be.
Tenmoku are known for their variability. During their heating and cooling, several factors influence the formation of iron crystals within the glaze. A long firing process and a clay body that is also heavily colored with iron increase the possibility for iron from the clay to be drawn into the glaze. As the glaze melts, iron can migrate into the glaze to form surface crystals, as in the “oil spot” glaze, or remain in solution deeper in the glaze for a rich, brilliant color. Oil spots are more common in an oxidation firing.
Tenmoku cup debris on display at Jingci Temple Art Museum, Hangzhou, China ©Xinhua News
A longer cooling time allows for maximum surface crystals. Potters can "fire" a kiln to achieve this effect. During a normal firing, the kiln is slowly brought to a maximum temperature by adding fuel, then the fuel is turned off and the kiln is allowed to cool slowly by losing heat to the surrounding air. To extinguish a kiln, the potter continues to add a limited amount of fuel after the maximum temperature is reached to slow the cooling process and keep the glazes molten for as long as possible.
