Compare the similar vase with the more usual tea-dust glaze, and Qianlong mark, illustrated in Porcelain from the Tianjin Municipal Museum, Hong Kong, 1993, no. 162. Another is illustrated by R. Krahl in Chinese Ceramics in the Meiyintang Collection, vol. 2, London, 1994, p. 256, no. 935, and another is illustrated by J. Ayers in Chinese Ceramics, The Koger Collection, London, 1985, p. 164, no. 135, where the author notes that the darker glaze is typical of the later period. See, also, the similar Qianlong-marked vase from the Goldschmidt Collection sold at Sotheby's Hong Kong, 13 November 1990, lot 64.