Previously sold at Christie's New York, 20 September 2001, lot 387.

It has been suggested that these washers are moulded with small bosses symmetrically spaced around the outside of the exterior to simulate 'drum-nails'. The implication therefore is that these washers are in some way similar to a percussion instrument familiar to Court connoisseurs both of music and porcelain, perhaps like tambourines. The small spur marks around the underside are carefully positioned for miniature stilts to protect the vessel during firing, since there is no unglazed surface or edge to facilitate this on these completely glazed washers. Slip decoration is unusual to find on monochrome wares; while it allows greater freedom in the design to be applied, it is by definition much more labour intensive than simply moulding a design, and more prone to less than absolute precision in the layout of the pattern. The double vajra design at the centre of the interior first appeared as a decoration on ceramic during the 15th Century, where it probably suggested its origins in the symbolism of Tibetan Buddhism on wares with a religious or ritual purpose.