The original rough boulder of the present brushwasher would have been of considerably large size. It is interesting to note the artist's ability in working the natural irregular form of the boulder to convey an overall ethereal theme of dragons emerging out of dense clouds, permitting a portrayal of inquisitive dragons resting their heads just above the mouth rim of the vessel. The interior is well hollowed whilst the thick sides are carved in high relief on the exterior to provide the viewer with a sense of depth created by the multiple layers of clouds.
The unusual treatment of the whirlpool on the underside where it forms the base of the vessel appears on earlier jade carvings dating to the 16th/17th century Ming dynasty period, such as the white jade mythical dragon-tortoise shaped water container, included in the exhibition, Arts from the Scholars Studio, University of Hong Kong, 1986, p. 158, no. 131; and a large spinach-jade bowl from the Bamble North collection, sold at Sotheby's London, 18 June 1968, lot 150.
The earliest example of this form of wave-like base on jade is a massive wine basin measuring 493 cm. across the body, carved in shallow relief with mythical sea creatures on the exterior, and known as the Dushan dayuhai, the 'Du Mountain Wine Sea'. This basin, used as a wine vessel, was believed to have been commissioned by Khubilai Khan, who placed it in the Guanghan Palace on the Hill of Myriad Years, located on an island on Beihai Lake in Beijing. The vessel disappeared during the turbulent transitional years between the Yuan and Ming dynasty, although its existence was known during the Ming period. The basin was later rediscovered by Emperor Qianlong in 1745, who found priests using it as a container for preserved vegetables. Qianlong was so impressed with the basin that he composed three poems based on the vessel and had the text inscribed onto the vessel. The Qianlong jade vessels of this theme appear more regular in form, such as the large green jade vessel, formerly from the H. R. Bishop collection, now in the Metropolitan Museum of Art, p. 30; the white jade example in the collection of Lady Lever, illustrated by S. C. Nott, Chinese Jade, London, 1936, pl. C1; and spinach-green brushwasher dated to the Kangxi period, sold at Christie's Hong Kong, 29 May 2007, lot 1401.
The imagery of dragons emerging out of clouds is a popular theme disseminated from Southern Song dynasty paintings traditionally attributed to the renowed artist Chen Rong (circa 1189-1259). Compare a handscroll painting attributed to Chen Rong depicting a single dragon striding out of misty clouds, in the Palace Museum collection, Beijing, illustrated in Zhongguo Huihua Quanji, Zhejiang Renmin Meishu Chubanshe, vol. 4, 1999, p. 171, no. 132; and another depicting nine dragons by the same artist in the Boston Museum of Fine Art, illustrated, op. cit., pp. 166-9, nos. 127-130. The dragons on the Boston handscroll are variously portrayed rising out of crested waves, clambering on jagged rocks, half-submerged in clouds and in pursuit of a pearl. All these attributes clearly provided the inspiration for later works of art, particularly in scholar's objects, such as present brushwasher.