Our daily-use ceramics usually wear glossy and smooth clothes, especially daily-use ceramics. We pay more attention to "clothes". Some are as white as jade, and some are colorful and very beautiful. This kind of clothes made of ceramics is called "glaze". Glaze means oily luster in Chinese characters, so the word "oil" is used to express the luster of porcelain surface. However, because the word "oil" represents food, the word "color" means luster, which was modified by later generations and added the word "you" to form the word "glaze". So why does the glaze make the surface of the ceramic cup smooth?
1. glaze is a continuous glassy layer attached to the surface of ceramic body, or a mixed layer of glass and crystal. The glaze may be made of calcium containing stone and charcoal ash used in ancient stone cooking, or consciously made of shell powder inspired by the beautiful texture of shell surface. In fact, as early as the Shang Dynasty more than 3000 years ago, our ancestors had learned to use rock and clay to make glaze to decorate ceramics. In the Han Dynasty, paper warm lead glaze with lead as cosolvent was invented. Later, ceramic artists used the phenomenon that kiln ash naturally fell on the green body and could become glaze, and then used plant ash as the raw material for making glaze.
2. Generally, the glaze thickness is only 1% - 3% of the body thickness, but after firing in the kiln, it fits closely with the porcelain body, making the porcelain dense, soft luster, impermeable to water and gas, and giving people the feeling of being as bright as a mirror. At the same time, it can improve the use intensity, prevent pollution and facilitate cleaning.
3. There are many kinds of glaze, which can be divided into porcelain glaze, ceramic glaze and flint glaze according to the body type; According to the firing temperature, the glaze below 1100 ℃ is called low-temperature glaze, the glaze between 1100 ℃ and 1250 ℃ is medium temperature glaze, and the glaze above 1250 ℃ is high-temperature glaze. According to the classification of glaze characteristics, white glaze is probably due to people's love for silverware. Colored glass is deeply loved by people for its colorful colors. The patterns in the crystal glaze are beautiful and moving, and the kiln glaze is dazzling and beautiful. The glaze is clear, elegant and unique.