ZHENGDE SIX-CHARACTER MARK IN UNDERGLAZE BLUE WITHIN A DOUBLE CIRCLE AND OF THE PERIOD (1506-1521)

Compare with a Zhengde zhadou enamelled on the exterior in coral-red and glazed white on the interior, exhibited at the International Exhibition of Chinese Art, Royal Academy of Arts, London, 1935, no.2705; also a smaller one decorated with scattered flowers and insects, sold at Christie's New York, 24 September 2021, lot 948.