Yongzheng's keen interest in the antique revival, is represented here on the glaze which is imitating the nice guan celadon glaze from the Song dynasty.
For a Song prototype compare the Southern Song guanyao vase of very similar size and form in the British Museum, illustrated in Oriental Ceramics, The World's Great Collection, vol. 5, 1981, col. pl. 24.
A Qianlong-marked vase of similar size and form, but covered with a tea-dust glaze, is illustrated in The Baur Collection, Geneva, 1972, vol. III, no. A392, together with a slightly smaller 'clair-de-lune' vase with Kangxi mark, no. 317.
See another guan-type compressed vase with Yongzheng sealmark sold in our Hong Kong Rooms, 27 May 2009, lot 1888 ; and a Qianlong example also sold in our Hong Kong Rooms, 27 May 2008, lot 1799.