Ru ware

By Ceramic Design

Like Ding ware, Ru (Wade-Giles: ju) was produced in North China for imperial use. The Ru kilns were near the Northern Song capital at Kaifeng. In similar fashion to Longquan celadons, Ru pieces have small amounts of iron in their glaze that oxidize and turn greenish when fired in a reducing atmosphere. Ru wares range in colour—from nearly white to a deep robin’s egg—and often are covered with reddish-brown crackles. The crackles, or “crazing,” are caused when the glaze cools and contracts faster than the body, thus having to stretch and ultimately to split, (as seen in the detail at right; see also ). The art historian James Watt comments that the Song dynasty was the first period that viewed crazing as a merit rather than a defect. Moreover, as time went on, the bodies got thinner and thinner, while glazes got thicker, until by the end of the Southern Song the ‘green-glaze’ was thicker than the body, making it extremely ‘fleshy’ rather than ‘bony,’ to use the traditional analogy (see section on Guan ware, below). Too, the glaze tends to drip and pool slightly, leaving it thinner at the top, where the clay peeps through.

As with Ding ware, the Song imperial court lost access to the Ru kilns after it fled Kaifeng when the Jin invaded, and settled at Lin’an in Hangzhou, towards the south. There the Emperor Gaozong founded the Guan yao (‘official kilns’) right outside the new capital in order to produce imitations of Ru ware. However, posterity has remembered Ru ware as something unmatched by later attempts; Master Gao says, “Compared with Guan yao, the above were of finer substance and more brilliant luster.”