The shape of the current you is based on a Shang prototype, such as the one recorded in the Xiqing xujian, the Imperial inventory of archaic bronzes. However, the craftsmen have taken great liberty in the interpretation of the taotie masks, creating fantastic abstract shapes and form with a wide range of interesting colours. Compare an example in the Summer Palace (Yiheyuan) Collection which is closely related to the current vessel but dated to the Qianlong period by the researchers of the catalogue, illustrated by Gao Dawei in The Summer Palace Collection, Intercontinental Press, Beijing, 2000, p. 128. Compare also the example in the Palace Museum, Beijing, which has very similar designs of taotie masks with the Summer Palace example but is enamelled all over in dark green, and is illustrated in The Complete Collection of the Treasures in the Palace Museum - Metal-bodied Enamel Wares, Hong Kong, 2001, no. 147. Another example from the Dr. Gunhild Avitabile Collection, very similar to the Summer Palace you, is illustrated in the exhibition catalogue Die Ware aus dem Teufelsland, Hannover, 1981, p. 151, no. 81. Compare also the example in the National Palace Museum, Taipei, illustrated in Masterpieces of Chinese Enamel Ware in the National Palace Museum, Taipei, 1973, no. 23, which is more slender in proportion and more austere in its design.