This interesting combination of transparent glass overlay carved through to an opaque ground is typical of glass vessels made at the Imperial workshops located within The Hall of Cultivating the Mind, Yangxindian, that were set up in the Kangxi period and continued throughout the Yongzheng and Qianlong periods. Compare with related overlay glass vessels dated to the Qianlong period in the Palace Museum, Beijing, illustrated in Zhongguo meishu quanji - Gongyi meishu bian, vol. 10, Beijing, 1987, pls. 263-77. Most of the Beijing examples bear Qianlong reign marks engraved in standard script. The subtle and complementary contrast of the two colours of the present vase is quite unusual.