QIANLONG SIX-CHARACTER SEAL MARK IN UNDERGLAZE BLUE AND OF THE PERIOD (1736-1795)

Compare to a nearly identical Qianlong vase in the Nanjing Museum, illustrated in The Official Kiln Porcelain of the Chinese Qing Dynasty, Shanghai, 2003, p. 235 and another example in the National Palace Museum, Taipei, illustrated in Porcelain of the National Palace Museum, Blue-and-White Ware of the Ch'ing Dynasty, CAFA, Book II, 1968, pl. 2.