Yaozhou Kiln

Yaozhou ware (Chinese: 耀州窯; pinyin: Yàozhōu yáo; Wade–Giles: Yao-chou yao) is a type of celadon or greenware in Chinese pottery, which was at its height during the Northern Song dynasty. It is the largest and typically the best of the wares in the group of Northern Celadon wares. It is especially famous for the rich effects achieved by decoration in shallow carving under a green celadon glaze which sinks into the depressions of the carving giving contrasts of light and dark shades.

Although "the term Northern Celadon has never been regarded as anything but vague and unsatisfactory", and the Yaozhou kiln site has been known for a long time, some scholars have felt that the wider term retains its usefulness as an umbrella category and because of the difficulty of distinguishing Yaozhou wares from those of other sites. The most important of these are at Linru and Baofeng in Henan, but their quality is regarded as inferior to Yaozhou, although the bodies are extremely similar, and the range of glaze colours overlap. The "products are only distinguishable by very small technical differences in the carved wares and of style in the moulded ones".

Yaozhou and the other Northern Celadons have a clay body that fires to a light grey under glaze, and a "yellowish to olive-brown where exposed". The glaze is transparent, at least until later examples, and lacks the opalescence that Longquan celadon received from millions of tiny gas bubbles trapped in the glaze, as well as the grey and blue tints that the green of southern wares could achieve. Instead the colour "tends to yellowish or muddy brown tones", generally where the reducing atmosphere is not strong enough.

The wares are fired to stoneware, in Western terms, though qualifying as "high-fired" in Chinese terms, which is often translated as porcelain. Like other celadons, the glaze colour is given by iron oxide fired in a reducing atmosphere. The kilns were fired by coal, and until the final years saggars were used. A characteristic northern type of "horseshoe-shaped" or mantou kiln was used, named after the Chinese bun it resembles in shape; one of a group excavated at Yaozhou was unusually well-preserved, allowing accurate plans to be made. Towards the end, after saggars were abandoned, a ring was left unglazed in the centre of vessels, which avoided pieces stacked directly in piles from sticking together, but detracts from their appearance.

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Wikipedia