This teacup with a so-called tortoiseshell glaze is a fine example of southern ware from Jizhou, where potters specialized in brown splashed glazes sometimes resembling partridge feathers or tortoise shells. The variety of dark glazes and vessel types produced by the Jizhou kilns are evidence of the popularity of black ware at the time. Jizhou kiln potters competed with the Jian kilns which produced almost exclusively teacups, such as the Black-Glazed Teabowl (CMA 2020.176) and the Black-Glazed Teabowl with Incised Characters (CMA 2020.175).