The current form is inspired by Western Zhou archaic bronze vessel, such as a zun illustrated in Xiqing gujian, juan 8 (fig. 1). It was first adopted on porcelain during the Yongzheng period in a variety of glaze colours including Guan-type, Ge-type, celadon, blue, teadust and in blue and white. For a similar Qianlong-marked Ru-type glazed vase, see an example illustrated by Reginal Krahl, Chinese Ceramics in the Meiyintang Collection, vol. 2, London, 1994, no. 873.