Under Ming royal patronage, potters at Ching-te-chen introduced a series of fine porcelains decorated with new and improved overglaze polychrome enamels. The term wu-ts'ai
means "five colors" but it was used generically to mean "polychrome" regardless of how many colors actually appeared on a vessel. The Wu-ts'ai overglaze colors included red, blue, green, yellow, and purple, and during Ming, they were usually used in conjunction with underglaze cobalt blue designs. The Wu-ts'ai palette gained favor during the Chia-ching (1522-66) and Wan-li (1573-1620) periods and was produced at imperial as well as private kilns.
Made at Ching-te chen, this rare, porcelain brushrest bears a six-character Wan-li reign mark on its base. It is moulded in the form of a three-peak mountain with a dragon in relief encircling each peak. The central dragon and some motifs are outlined with underglaze cobalt oxide, while the flanking dragons, mountains, waves, clouds, and cusped apron are painted with red, yellow, and green with some black outlining all in overglaze enamels. The development of overglaze polychrome enamels is one of the most important contributions of the Ming potter to ceramic history.