The present lot is unique as only one other washer of this exceptionally rare form appears to be published. Compare to a similar ivory mallow-form tray, illustrated Bamboo, Wood, Ivory and Rhinoceros Horn Carvings, The Complete Collection of Treasures of the Palace Museum, Hong Kong, 2002, p. 202, no. 166. Both have been carved and decorated remarkably with their leaves and insects picked out in blue colour. The delicate carving and naturalistic rendering of the mallow leaf are characteristic of the extraordinary artistry during the 18th century.