China Since early times the Chinese have searched for methods of improving the technical quality of ceramics and the efficiency of production. Early innovations in ceramic technology included the use of kilns with separate combustion and firing chambers and the introduction of the potter's wheel. Ceramic molds were an essential part of the bronze casting process, and from the third century B.C.E. mold technology was adapted for the production of ceramic funerary sculpture placed in tombs of rulers and nobility. The seven thousand figures of the celebrated Terracotta Army were created with a limited number of molds used in different combinations to produce an impression of infinite variety. High-fired glazes had been introduced during the second millennium B.C.E., but it was not until a decline in bronze and lacquer manufacture in the late Han period (206 B.C.E. to 220 C.E.), that their production became widespread. Tea drinking, which gained popularity in the centuries following Han, helped foster their acceptance. By the eighth century Lu Yu, in his Classic of Tea, stipulated ceramic tea bowls as most suitable for tea drinking, giving pride of place to wares of the Yue kilns on account of their subtle green "celadon" glaze. Porcelain had been developed as early as the sixth century but until the fourteenth century remained essentially monochromatic. It was probably the stimulus of the Islamic market that inspired Chinese potters to decorate porcelain using cobalt pigment. With the establishment of the Ming dynasty (1368-1644), the court became the most important arbiter of ceramic taste, ordering huge quantities of porcelains from official kilns at Jingdezhen and imposing rigorous standards of quality.