Warring States Period 475-221 BC

Jar with Ribbed Decoration
4th century BC
Stoneware with yellowish green glaze
The glaze on this piece was probably made from sifting dry ash over the damp pot after it was formed.  This piece is an example of proto-porcelaneous ware, the predecessor of finer kaolin type high fire clay bodies developed in the late Tang Dynasty. Pieces like this one will often be stamped in fine patterns instead of incised.  The shape of this jar as well as the small handle type imitates a bronze form called a jian that was a ritual water vessel. 

images from the Museum of east Asian Art, Bath, England