This gracefully proportioned and richly glazed vase is an imitation of Song dynasty vases of the same form which in turn are modelled archaic jade cong from the Neolithic period. For a Guan vase of cong shape dating to the Southern Song dynasty, in the of Tokyo National Museum, refer to Oriental Ceramics, The World's Great Collections, vol. 1, Kodansha series, Tokyo, 1976, col. pl. 13. The present vase with its attractive greyish-blue glaze probably found its inspiration from the Northern Song Ru ceramics rather than those of the Southern Song Guan wares. The decorative form of the present vase, with its unusual moulded inverted U-shaped design on each facet and the additional apertures, is particularly rare. On many archaistic ceramic forms of the Qing period, perforations are applied on outer side of the circular foot in imitation of archaic bronze shapes, such as those found in Guan-glazed hu-shaped vases from the Song dynasty. It can be argued that for tall hu-shaped vases these apertures probably served the purpose of stabilising their slimmer profile, however, with the sturdier cong shapes this feature seemed oddly unnecessary. A comparable example of this exact same size and design, covered with a Ge-type glaze was sold at Christies Hong Kong, 29 April 2002, lot 665. Two other Guan-glazed Qianlong-marked vases of this same moulded design are known. The first with perforations on outside of the ring foot, from the Carl Kempe Collection, was sold at Sothebys Paris, 15 December 2011, lot 98; and the other without any apertures was sold at Sothebys Paris, 7 June 2011, lot 197. Related examples of cong-shape but moulded with trigrams are known such as the Qianlong-marked Ge-glazed vase illustrated by Peter Y.K. Lam, Ethereal Elegance, Porcelain Vases of the Imperial Qing, The Huaihaitang Collection, Art Museum, The Chinese University of Hong Kong, 2007, pp. 172-173, no. 45; and an another from the Edward T. Chow Collection, was sold at Sothebys Hong Kong, 19 May 1981, lot 503.