The glaze on this rare vase is based on one of the 'Five famous wares of the Song dynasty' - Ge ware. The other four famous wares are Ru, Guan, Ding and Jun. All five of these Song dynasty wares were greatly admired by the emperors of the high Qing, and during the Yongzheng reign much research and development was undertaken in order to reproduce these glazes on the porcelains made at the imperial kilns at Jingdezhen. Like his father, the Qianlong emperor was fascinated by antiques and encouraged the craftsmen working for the court to reproduce them. In some instances, he even had pieces inscribed Qianlong fang gu (literally, ‘Qianlong copying the ancient’).
The Ge-type glaze on the current vase is especially successful, reproducing the close crackle and slight translucency of the glaze to very good effect. Two Song dynasty hu-form vases which may have inspired the present vase, from the Qing Court Collection, are illustrated in The Complete Collection of Treasures of the Palace Museum - 33 - Porcelain of the Song Dynasty (II), Hong Kong, 1996, p. 45, no. 39 (with a Ge glaze), and p. 113, no. 101 (Longquan ware, with a celadon glaze). Compare, also, the Qianlong fanghu-shaped Ge-type vase, illustrated in Chinese Ceramics in the Idemitsu Collection, Japan, 1987, no. 960.