The center of production for Yixing zisha pottery is Dingshuzhen in Yixing County, in the southern part of Jiangsu Province. High quality Yixing clay comes from along the banks of Lake Tai near Nanjing. Refined and fired to a high temperature it produces a slightly absorbent pottery highly regarded by tea lovers.
This has been the center of Chinese teapot production since the Song Dynasty (960-1279). In the Ming period several generations of famous zisha potters worked there. In the Qing period literati collaborated with zisha potters to produce large numbers of finely made teapots and decorative items appealing particularly to the literati taste.
A good Yixing teapot should pour evenly from the pot, have a porcelanious ring to it when struck, a very snug fitting lid which if the lid has a hole will stop pouring when you put your finger over it. Since the clay will absorb some of the flavor it is important to drink only one kind of tea out of it. If it has any age to it, it should have a distinct residue of old tea inside.
Potteries in Yixing xian, which lies west of Taihu (Lake Tai) in Jiangsu Province, were operative as early as the Han dynasty, when they produced gray- and red- bodied earthenware as well as green-glazed stoneware. 23 The ceramics for which kilns in this vicinity are most famous, however, are of a much later date and of a very different nature. The variety of clays available to these kilns fire to many different colors, ranging from buff to reddish brown to dark chocolate brown; they also lend themselves to the creation of interesting textures as well as unusual and fanciful shapes.
Yixing kilns are famous for their unglazed reddish and brownish stoneware teapots, which are often embellished with incised, stamped, or relief decoration. These Yixing teapots were extensively copied in Holland, England, and Germany in the late seventeenth and the eighteenth centuries.
Based on recent kiln~site discoveries, the distinctive type of Yixing stoneware, which is called zisha ("purple clay") ware in China, is thought to have developed during the Northern Song period. 24 A few excavated teapots document its manufacture during the sixteenth and seventeenth centuries, 25 and production has continued to the present day. Many Ming and Qing Yixing wares have been signed by potters whose dates are known, and a number of these pieces are accepted as genuine. However, with typical Chinese reluctance to part with the past, Yixing craftsmen have sustained old styles over long periods of time, making it difficult to give an exact date to the majority of these wares. Indeed, it is hard to distinguish some modern Yixing teapots from examples that were produced during the Ming and Qing periods.
A zisha ware with a Jun-type glaze, called Yijun ware, rivals the flambé Shiwan ware from Guangdong.
The surface of the vast majority of Yixing wares simply displays the body material of the vessel with molded, carved or applied decoration. Glazing or surface painting are rare. A small number of Yixing wares are glazed, usually with a robin's egg glaze, as in the case of a square 18th century teapot in the K.S. Lo collection illustrated in Yixing Purple Clay Wares, Hong Kong, 1994, p. 81, no. 33, or a Jun-type glaze, as in the case of a small Kangxi seal-paste box in the Percival David Foundation illustrated by R. Scott in For the Imperial Court - Qing Porcelain from the Percival David Foundation of Chinese Art, Singapore/London, 1997, p. 107, no. 38. Painted decoration is particularly rare and may take the form of enameled decoration like that of a 19th century teapot in the K.S. Lo Collection illustrated in Yixing Purple Clay Wares, op. cit., p. 109, no. 64. Much more in keeping with the literati aesthetic, however, is the subtle and refined painting in natural slip colors.