In A Dictionary of Chinese Ceramics, Singapore, 2002, p. 47, Wang Qingzhen quotes old sources that state that this type of vase with iron-red decoration and no reign mark was only made during the Qianlong period as court gifts to Tibetan monks. Their production ceased after Qianlong's reign, as Tibetan monks no longer came to court. An identical vase dated to the Qianlong period and in the collection of the Nanjing Museum, is illustrated by Xu Huping in The Official Kiln Porcelain of the Chinese Qing Dynasty, Shanghai, 2003, p. 225, where its use is explained. A pair of vases in the collection of the National Palace Museum is illustrated in Monarchy and Its Buddhist Way: Tibetan-Buddhist Ritual Implements in the National Palace Museum, Taipei, 1999, p. 184, no. 91.