Explanation

Also known as lime glaze, it is one of the traditional high-temperature glaze varieties in China. It mainly uses CaO (calcium oxide) as the main flux. CaO usually comes from materials such as plant ash, limestone and glaze fruit. CaO content in plant ash is as high as 15% to 20%. In addition, plant ash also contains other elements, such as SiO2 (silicon dioxide), Al2O3 (aluminum oxide), Fe2O3 (iron oxide), K2O (potassium oxide), MnO, P2O5, etc., which are necessary for the formation of glaze. Among them, phosphorus can promote glaze to produce liquid-liquid phase separation under high temperature, thus forming opacification and a series of unique artistic effects. For example, the floral sleeves in the glaze of Jiaxian Kiln in the Tang Dynasty, the azure and moonlight in the glaze of Jun Kiln in the Song Dynasty, the rabbit hair and oil drops in the glaze of Jian Kiln in the Song Dynasty, and the liquid-liquid phase separation in rare colored glazes such as tortoise shell in the glaze of Jizhou Kiln are all related to the existence of phosphorus. After the Shang Dynasty, glaze ash gradually began to be used instead of plant ash. glaze ash is the product of burning limestone together with plants. When preparing glaze, china stone with high flux content (such as glaze fruit in Jingdezhen) is used and mixed with appropriate glaze ash to prepare glaze. The characteristics of lime glaze include low viscosity under high temperature, easy flow, glaze layer can not be too thick, strong transparency, good glaze luster, and large hardness of glaze. Its maturity temperature is usually between 1200 and 1250 degrees Celsius. lime glaze not only has good transparency, but also contributes to the coloration of many colors. Especially in the preparation of blue and white, copper red, iron blue, chrome green and other color glazes, only the use of lime glaze can get a better color effect. lime glaze plays an important role in the production of Chinese traditional ceramics, and provides a variety of color choices for ceramics.

Classification