Jun ware jar

From Henan province, northern China
Song dynasty, 12th century AD

A blue jar with purple splashing: an optical illusion

Jun wares are counted among the 'five great wares' of China, along with Ding, Ru, Guan and Ge. A number of kilns in Henan province produced Jun wares, starting in the Tang dynasty (AD 618-906), with production hitting a high point in the Song dynasty (960-1278), and continuing until the fifteenth century.

Jun wares fall into four categories, according to their appearance: green, lavender-blue, lavender-blue with purple splashes, like this jar, and purple-and-blue streaked. This is more or less the chronological order in which they appeared.

The blue colour of the glaze is an optical illusion, resulting from a chemical reaction that occurs during the firing and cooling process. Most of the body is thickly glazed, but thinly-glazed areas appear almost white. The purple splashes were produced by adding copper oxide to the glaze. Prior to Jun wares, iron oxide had been used to create reddish colours and the use of copper was extremely rare. Most of the best Jun wares pieces were fired twice in order to get the correct glaze effects.

S.J. Vainker, Chinese pottery and porcelain, (London, The British Museum Press, 1991)