Xingyouheng tang is the studio name of Zaiquan (1794-1854), who became the Fifth Prince Ding in 1836 upon the death of his father. For details, see Peter Y. K. Lam, 'Studio Marks in Imperial and Court Related Snuff Bottles,' The Imperial Connection. Court Related Chinese Snuff Bottles. The Humphrey K. F. Hui Collection, p. 41. The crystal bottle used is precisely what one would expect of contemporaneous inside-painted crystal bottles by Gan Xuanwen, of Lingnan, produced at the time the Prince was alive. In this case, the gilding also appears to be of very considerable age, and is probably original. Works from the mid-Qing period with inscriptions, particularly on crystal, but also on some other materials, were often filled with colour, usually in gold, red, and, more rarely, green.