High quality Yi-hsing ( Yixing ) clay comes from along the banks of Lake Tai near Nanjing. Yixing County is in the southern part of Jiangsu Province.
The clay used for Yixing pottery is called Zisha ("Purple clay") despite the fact that it is not always purple in color neither unfired or fired. The high content of metallic oxides in the clay body resulted in wares ranging from purple to beige or green, the variation in color being caused by differences in kiln temperature and atmosphere.
Another yellow clay called
shih huang (stone yellow) which turned to dark brown. A clay which produced a "pear skin" color. A light scarlet clay produced a porrtery of the colour of pine spikelets. A light yellow clay making a green ware and aniother producing a light red pottery.
Engraved designs cut in the ware while it was still soft. These are usually inscriptions of a poetic nature, great importance being attached to the calligraphy.
From the earliest days of their importation, the Yi-shing wares have been known in Europe, especially in Italy, Spain, and Portugal, by the Portuguese name of
buccaro.
Another important group of Yi-hsing wares presents an entirely different aspect, and indeed it is little understood in Europe.
Original glazed wares are rarer today than their Chun Chou prototypes. There is no reason to suppose that early successorts have not kept up the continuity of the manufacture. It is very much alove today.
Certain types of glazed pottery is distinguished by a concave base which serves instead of the usual hollowed out foot and foot rim, and by a glaze which stops a little short of the base in an even, regular line which is quite distinct from the wavy glaze line of the earlier wares. A jar of this type in the British Museum has a typical Yi-hsing glaze. It is suggested that this peculiar finish in an indication of Yi-hsing manufacture.
