This cup belongs to a very small group of imperial quality porcelains which can be related to Tang Ying (1682-1756), a cultivated scholar and the influential superintendent of the Imperial kilns in Jingdezhen. Tang Ying was a Vice-Director of the Imperial Household Department before appointed to the Jingdezhen factory in 1726, then started his long and illustrious career at Jingdezhen which lasted 25 years under the Yongzheng and Qianlong reigns. His experience and insight into the problems of porcelain production allowed him to make essential changes in the structure of the factory. Under his guidance, both technical improvement and the artistic perfection were achieved. For a further discussion on Tang Ying, cf. Peter Y.K. Lam, 'Tang Ying (1682-1756): The Imperial Factory Superintendent at Jingdezhen', Transactions of the Oriental Ceramic Society, vol.63, 1998-9, p.65, where the author identified a number of Tang's work in private and public collections worldwide.

Tang Ying was regarded as a competent potter, painter and calligrapher. There exist a small number of exquisite pieces without reign marks carrying Tang Ying's trademark seals and signature. These rare masterpieces are apparently designed by him with exceptional quality, decorated with Tang's painting and inscribed with his poems. The current cup must be one of the last pieces made under his supervision before he retired from office in 1756. On one side at the end of the poem with two red seals reading Hanand Mo, 'brush' and 'ink', while the other side on the upper right corner a seal reading Pianyue, crescent moon, followed by the poem, terminated with the cyclical date Yihai, corresponding to 1755, and ending with two iron-red seals reading Tao zhu, which was a pseudonym used by Tang Ying. All these seals are recorded as those used by Tang Ying in the Special Issue Commemorating the Tercentenary of Tang Ying's Birth, Jingdezhen Taoci, 1982, no. 2. 

A brushpot in the collection of the Art Museum, Chinese University of Hong Kong, decorated in sepia enamel with a dragon, inscribed in the same calligraphy with a poem signed by Tang Ying and with the same seal Pianyue, is illustrated by P. Lam, op. cit., 1998-9, p. 69, figs. 5 and 6. A famille rose vase from the collection of Paul and Helen Bernat, sold at Sotheby's Hong Kong, 15 November 1988, lot 52, and again at Christie's Hong Kong, 29 April 2001, lot 516, also bears an inscription by Tang Ying, followed by the seals Han Mo.

Christie's. Important Chinese Ceramics and Works of Art. 1 December 2009. Hong Kon