Tea Bowl with 'Jin Zhan' Mark, Jian ware, Southern Song dynasty (1127-1279). Height 6.1 cm, Diameter of mouth 12.6 cm, Diameter of base 4 cm. © Shanghai Museum 

All decorated with black glaze, Jian wares in the Fujian region of the Song dynasty had very distinctive varieties. The tea competition popular among royalty in the Song dynasty was a game to see whose tea mark would remain for the longest time. Therefore, black porcelain was used to highlight the white tea dust. Jian wares became popular during this period, and later were also widely spread to Japan. This small cup in the Shanghai Museum was inscribed with two characters 'Jin Zhan', indicating it was a tribute to the imperial palace.