Jar with flat mouthrim

Unlike conventional Shang jars, this vessel's flat mouthrim and wide shoulder tapering to a convex base comprise a shape seen in the repertoire of early northwestern potters. Numerous similar jars found in the Shaanxi-Longshan stratum served as the prototype of this shape (WW 1984.7: 30-41). Early Western Zhou jars were either impressed with cord patterns or left with the flat surface undecorated. But beginning in the middle Zhou, designs of one to nine grooves commonly encircled the mouthrims, shoulders, and bellies of such jars. The Zhou may have borrowed the technique of using grooves for decoration from the Shang tradition.