superbly potted with deep rounded sides rising from a short straight foot to a gently everted rim, the exterior evenly covered with a pale lime-green enamel, the interior and base left white, the latter inscribed in underglaze blue with a six-character reign mark within a double circle.

Provenance: Collection of Cheung Ling, Hong Kong.

Exhibited: Monochrome Ceramics of Ming and Ch'ing Dynasties, Min Chiu Society, The Hong Kong Museum of Art, Hong Kong, 1977, cat. no. 62 (the mark incorrectly illustrated as cat. no. 55a).
Exhibition of Ancient Chinese Ceramics from the Collection of the Kau Chi Society of Chinese Art, Art Gallery, The Chinese University of Hong Kong, Hong Kong, 1981, cat. no. 136.

Note: The current cup, with its vibrant lime-green enamel covering the exterior of its delicate porcelain body, is an exceptionally rare paradigm of the Yongzheng Emperor's pursuit of innovation and the influence of Jesuit technology. Despite having an abundant supply of lead-antimonate in China, it was not until the Jesuit missionaries had a direct influence on the manufacture of arts and crafts that Chinese potters started adding copper to lead-antimonate to produce the lime-green enamel seen on the current cup.

In addition to lime-green being among the rarest enamels used in the Yongzheng reign, the evenness of the enamel is also particularly noteworthy. The lime-green enamel would have required a second firing at a lower temperature and it is difficult to achieve a satisfactory result as seen on the current cup. See two lime-green examples in Taipei, one published in the Illustrated Catalogue of Ch'ing Dynasty Porcelain in the National Palace Museum, Republic of China: K'ang-hsi Ware and Yung-cheng Ware, Tokyo, 1980, pl. 153; and the other included in the exhibition Qingdai danse you ciqi tezhan [Special exhibition of monochrome glazed porcelain of the Qing dynasty], Taipei, 1981, pl. 44. See also a similar pair included in the exhibition Shimmering Colours. Monochromes of the Yuan to Qing Period: The Zhuyuetang Collection, Art Museum, The Chinese University of Hong Kong, Hong Kong, 2005, cat. no. 113.

Related examples with reign marks inscribed within double squares include a pair sold in these rooms, 7th April 2011, lot 30, from the Meiyintang collection; and a single cup also sold in these rooms, 15th November 1988, lot 68, from the collection of Paul and Helen Bernat. Compare also a lime-green enamelled cup, with a more hemispherical form, offered in this sale, lot 3116.

Sotheby's. Qing Imperial Porcelain A Private Collection, Hong Kong, 08 Oct 2019, 10:00 AM