The Chinese term for orange peel is "ju-pi" (chu-p'i). "Orange peel" or "chicken skin" refers to the same glaze appearance and were named thus because the surface of the glaze resembled the texture of an orange peel or a chicken skin. This phenomenon occurs on Ge and some Guan wares as far back as the Song period. It also occurs on many Ming monochromes as well, particularly sacrificial red or blue. It became a deliberate design element during the Yongzheng and Qianlong periods seen mostly on monochromes (i.e. many copper red items) but did occur on other types as well.