The form of this rare, archaistic zun-shaped porcelain vase was one that found considerable favour with the Wanli court, as evidenced by the pair of smaller vases of this form, with aubergine decoration on a yellow ground, which were excavated in 1958 from the Dingling tomb of the Wanli emperor, see Zhongguo wenwu qinghua da cidian - Taoci juan, Shanghai cishu chubanshe, 1995, p. 404, no. 803. Although there were several versions of the ancient bronze zun form made in porcelain over the centuries, the form seen on the vases from the Wanli emperor's tomb and on the current vase is the most successful and one of the closest to the bronze original, bearing appropriate flanges. A similar version of this form, with the same shape of foot, but with slightly lower centre of gravity, is also occasionally seen among ceramic wares of the Jiajing reign. A Jiajing example with underglaze-blue fish decoration is in the collection of the Palace Museum, Beijing, cf. Zhongguo wenwu qinghua da cidian - Taoci juan, op. cit., p. 394, no. 769, while another Jiajing example with overglaze-green dragon decoration is illustrated by R. Fujioka and G. Hasebe in Sekai toji zenshu 14 Ming, Shogakukan, Tokyo, 1976, p. 198, no. 193.
The most striking examples of the zun form, however, are those larger vases, like the current example, which are decorated in wucai technique using underglaze-blue and overglaze enamels. What makes the current example especially rare and impressive, is the addition of turquoise enamel to the normal wucai palette of red, green, brownish-black and yellow enamels. There is another zun vase decorated in this expanded wucai palette with similar motifs in the Ataka collection, Osaka (Sekai toji zenshu 14 Ming, op. cit., pp. 104-5, no. 106). The dragons on the current example occupy a greater proportion of the decorative space, while the Ataka vase has one additional minor band of iron-red scrolls between the underglaze- blue classic scroll band and the multi-coloured petal band on the shoulder. Turquoise enamel was used with a little more frequency in overglaze palettes in the sixteenth and seventeenth century, as on pieces like the dishes in the Palace Museum, Beijing with red, green, yellow, black and turquoise enamels (The Complete Collection of Treasures of the Palace Museum 38 Porcelains in Polychrome and Contrasting Colours, Commercial Press, Hong Kong, 1999, pp. 3 and 24-5, nos. 2 and 22). However the inclusion of turquoise enamel with the wucai palette combining underglaze blue and overglaze enamel, as seen on the current vase, is very unusual in the Ming period. There are a few examples of vessels made for the Japanese market dating to the Tianqi or Chongzhen period (Transitional Wares and their Forerunners, Oriental Ceramic Society of Hong Kong, 1981, p. 135, no. 154), but porcelains with this palette made for the Wanli court and decorated with five-clawed dragons are exceedingly rare.