By the 1910s a taste developed among Western collectors for brightly colored mina’i (enamel-glazed) ceramics. While mina’i wares represent the prized collectibles of the day, they also serve to demonstrate the technical virtuosity of the Islamic potter and the evident demand within medieval Islamic society for functional objects of great beauty. The method for producing the polychrome enamel pigments is described in a treatise on pottery making by Abu’l-Qasim of Kashan, completed in AD 1301, by which time mina’i or haft rang (seven colors) wares, as they are known in the textual tradition, were no longer being produced.