Bowl with dragons, Stoneware with carved decoration, transparent glaze and copper rim mount, Ding ware, Quyang county, Hebei province, Northern Song dynasty, about AD 1086–1127. Height: 47 millimetres, Diameter: 170 millimetres, Sir Percival David Foundation of Chinese Art, PDF 114 © 2017 Trustees of the British Museum

This rare bowl is carved with a design of dragons inside with flowering plants outside. Ding potters pioneered the technique of fushao (firing a vessel upside down on its rim). Kiln managers saved on fuel by firing a greater number of pots at one time, stacking them in stepped saggars. The disadvantage was the unglazed mouth rim, cleaned free of glaze to avoid the vessel sticking to the saggar. Craftsmen used sheet copper and occasionally gold or silver, cut to size and heated to fit the rims to hide this flaw. Historical accounts suggest that dressing the rim with metal actually enhanced the status of the clay vessel.