A Short Guide to Jun Glaze and Ware

Historically speaking, Jun glaze vessels were introduced in the Henan province (China) - particularly in the counties of Linru and Yu - at the time of the Northern Song Dynasty, which was between 960 and 1126 BC. The use of this particular type of celadon or glaze became popular because of its beautiful effect on both ceramics and earthenware. As a result, production of Jun wares spread from Henan to nearby areas such as the provinces of Shanxi and Hebei, and continued from the Northern Song dynasty to the Jin and Yuan dynasties (1115 to 1368 BC). Kiln sites for Jun glaze vessels, along with artifacts, were discovered in the 1950s.

Jun ware gained popularity because of its unusual, thick, opaque glaze the primary element of which is straw ash. This usually produces a blue hue, but can be made to turn out other colors by considering two factors: the composition of the glaze, and the firing temperature in the kiln. What causes the blue hue has long been a puzzle to the modern world; however, breakthrough research has pinpointed to the presence of insoluble glasses in the glaze, as well as the reaction of these particles to light, as the reasons for the Jun ware's trademark appearance.

The "true blue effect" of a Jun glaze is evident in pieces fired at a temperature of about 1,300 degrees Centigrade. If a piece is subjected to a temperature lower than this, the resulting color would be grayish or "moon-white". And if a yellowish veneer is desired, all that needs to be done is to go below the minimum of 1,250 degrees Centigrade. Other colors can also be achieved; in fact, Jun ware in green, red, and lavender shades are also possible. The process of changing the temperature of the kiln to alter the color of a Jun-glazed vessel is called "yaobian".

Production of Jun vessels covered three dynasties, as mentioned in the first paragraph. This resulted in changes in appearance of Jun ware in each period. Pieces made during the Northern Song dynasty, for example, were thinner and featured a more thorough finishing. This is in contrast to pieces made during the Jin and Yuan periods, which often featured an uneven glaze (usually thinner around the rim and non-existent at the foot area).

As with other Northern Chinese celadons - which can refer to wares of a celadon or greenish hue, or to vessels that have a celadon glaze - Jun glaze vessels were popular among the upper class. Most of these were for everyday use by the wealthy; however, there were select pieces which were meant for palace or temple use. Also, as mentioned earlier, the Jun glaze was applied to both stoneware and ceramic pieces in a wide range of styles. Dishes with the distinct Jun glaze have been discovered, as well as spittoons, bowls, jars, flowerpots, and plates, among other things.