Basin with lavender-blue glaze, Ming dynasty, 15th century. Jun ware. Height 9 cm; Mouth Diameter 24 cm; Weight 1,458g. The ATAKA Collection. Gift of SUMITOMO Group, the ATAKA Collection, 00497 © The Museum of Oriental Ceramics, Photo NISHIKAWA Shigeru

This basin was covered with an opaque sky-blue glaze typical of Jun ware, to which copper oxide was added, and fired in reduced atmosphere, resulting in a bright reddish-purple exterior. The surface of the interior bears unique winding striations, which are called "earthworm tracks."15 spur marks and an incised Chinese numeral "two" are visible inside the foot ring. Jun ware basins and flower pots with Chinese numerals on the bases are made with scrupulous care, which implies that they were vessels for court use. Such works are also known as Guan (official) Jun. The numbers range from one to ten according to their sizes: one is the largest and ten the smallest. Initially such Jun ware were thought to have been produced in the Northern Song dynasty, but later studies found that they are more likely to be from the Yongle reign of the Ming dynasty.