The unusual Yongzheng seal mark on this vase is similar to that found on a similarly glazed censer illustrated in Shimmering Colours: Monochromes of the Yuan to Qing Periods, The Zhuyuetang Collection, Art Museum, The Chinese University of Hong Kong, 2005, p. 252, no. 172, where the glaze is referred to as an "archaic bronze" glaze. No. 173, a two-handled censer, is also covered with a similar glaze, which is additionally mottled in gold, and which has a Qianlong inscribed seal mark. A similarly glazed jardinière stand, which also has the same black Yongzheng seal mark, in the collection of the National Museum of China, is illustrated in Zhongguo guojia bowuguan guancang yanjiu congshu - ciqi juan, Qing dai, Shanghai, 2007, p. 101, no. 65.