The difference between underglaze and overglaze colors

No matter what type of plates or bowls you buy, you will find that as long as they are ceramic, there will be a special craftsmanship added to the outside. This layer of floral or different flower shapes will make people worry whether it is bad for the body? Or whether these patterns determine the material. In fact, this kind of pattern is called underglaze color and overglaze color. There is nothing to worry about. It is just a different classification and material. It has nothing to do with safety issues. Let me introduce to you the difference between underglaze color and overglaze color.

In simple terms:

Overglaze color refers to the process of painting various patterns on the fired white glaze or rough-bodied porcelain with pigments, which is then fired a second time in a low-temperature kiln at around 700℃-900℃ to solidify the colored materials at low temperature. Its color materials are widely used, the glaze colors are bright, the varieties are rich and the artistry is strong. Because the painting is applied on the glaze, it is easy to wear and tear and is easily corroded by acids and alkalis.

Underglaze color refers to the process of first painting a pattern on a semi-finished product and then applying glaze and firing it in a high-temperature kiln. After firing, the pattern is covered with a layer of transparent glaze underneath, making it appear crystal clear.

Underglaze color: The earliest prototype can be traced back to the Song Dynasty and has continued to this day.

Overglaze color: created in the Ming Dynasty based on underglaze blue and white painting.

In terms of time, underglaze color is older, and in terms of inheritance, it can be said that overglaze color originated from underglaze color.

2. The production steps and processes are different;

Underglaze color: Use colorants to decorate the raw or baked blanks with colored paintings, then glaze and finally fire them in a kiln. The glaze and painted patterns are fired at the same time, and the colorants fully penetrate into the glaze.

Overglaze color: The porcelain with a white porcelain body is first fired, and then the surface of the porcelain is decorated with colorants. It is then fired in a kiln. The painted patterns and glaze are fired separately.

Underglaze color: directly create on the raw body, just need to paint with colorant and then glaze, and then fire it in a kiln at about 1200℃ to 1300℃; if it is the method of underglaze painting on the raw body, first fire the clay body at 800℃ to make it raw body, and then fire it in a kiln at about 1200℃ to 1300℃ after painting and glazing.

Overglaze color: First use a kiln fire of about 1200℃ to 1300℃ to make a white porcelain blank, then paint it with colorants for decoration, and then use a kiln fire at 800℃ for a second time.