A VERY RARE RU -TYPE VASEYongzheng seal mark and of the period The elegant body of low shouldered form rising from a short inward-tapering foot and supporting a tall cylindrical neck flanked by tabbed handles, flaring to a rounded mouth, covered overall with a lustrous sky-blue glaze. 12.8cm (5in) high. 清雍正 仿汝小瓶 Provenance: Sotheby's London, 8 June 1993, lot 109 來源：蘇富比，倫敦，1993年6月8日，拍品109號 This rare vase is remarkable for its subtle bluish glaze, the purity of which accentuates the graceful curves of its profile. Created in imitation of the celebrated Ru -wares of the Song period, this vase reflects the Yongzheng Emperor's penchant for these early wares and the remarkable technical developments achieved at the Imperial kilns and made to meet the specific taste of the emperor. While a delicate celadon glaze had already been developed in the Kangxi reign, it was during the Yongzheng period that the production of glazes imitating Song dynasty Ru and Guan wares greatly expanded. According to the 1732 edition of the Jiangxi tongzhi (Jiangxi provincial gazetteer),piled by Xie Min, governor of Jiangxi Province between 1729 and 1732, two different types of Ru-type glazes were developed, one displaying a subtle network of crackles and the other of even tone; see S.W.Bushell, Oriental Ceramic Art , London, 1981, p.195. See a similar Ru -type vase, Yongzheng seal mark and of the period, which was sold at Christie's Paris, 8 December 2021, lot 184. Another similar vase, Yongzheng seal mark and of the period, was also sold at Christie's Paris, 23 June 2020, lot 128.