清乾隆

Compare to very similar style of slip-decoration on a Yixing brush pot by Yang Jizhu who was active during the Yongzheng and Qianlong periods (1723-1795) illustrated in Grace Wu Bruce, Elegant Offerings from the Scholar's Studio - the Jianzong Ge Collection, Hong Kong , 2002, p. 80, pl. 1. See also a Baishai Yixing brush pot also decorated with coloured slip dated to the Yongzheng period in the Palace Museum Beijing, Gugong Zhishi Congshu, Gugongcang Zishaqi, Beijing, 2001, p. 15, pl. 15.