The official kilns in Song Dynasty were directly built by the government, which were divided into the official kilns in Northern Song Dynasty and Southern Song Dynasty. It is one of the five famous kilns in Song Dynasty. The official kilns in the Northern Song Dynasty were called "old officials" and those in the Southern Song Dynasty were called "new officials". Among them, "old officials" are heavy, while "new officials" are light and thin. This is also an important feature and difference between the northern and southern official kilns. The carcass of the official kiln in the Northern Song Dynasty is thick, the fetal bones are dark gray, purple or black, and the glaze colors are light blue, pink blue and moonlight white. And Wen Ya's enamel is bright and moist, especially with big cracks on the glaze. Southern Song Dynasty official kiln ware, tires are black, dark gray, light gray, beige and so on. The thickness is different and the tires are delicate. The glaze color is opaque and multifaceted, and the glaze colors are pink blue, light blue, gray blue, moonlight white, beige and so on.
Ge kiln porcelain is one of the five famous kilns in Song Dynasty. The glaze on it belongs to matte glaze. The enamel is very thick, bright and smooth as cream, and delicate to the touch. The colors are rich and colorful, such as grayish yellow, grayish blue, beige, pink blue, moonlight white, oily gray and so on. A unique and important feature of Geyao porcelain is that the glaze of porcelain is cracked. Some cracks are light yellow and called "gold wire", while others are dark black and called "iron wire".