Also called “white jade. There are two types of frit, lead white and lead-free white, and each refers to frit that contains lead in its composition and frit that does not. Frit is an artificial vitreous ceramic raw material made from a homogeneous mixture of some or all of the ingredients necessary for glazes, which is melted into a glassy state and then quenched to form small lumps or pieces, and is mainly used for glazes. The purpose of this process is to make the chemical components necessary for glaze composition, such as alkali and acid, which are easily soluble in water, soluble in water by adding appropriate amounts of other components, such as alkaline earths, alumina, and silicic acid, to make them soluble in water and easy to use. It also has the effect of making it easier to introduce components that are difficult to dissolve at low temperatures into the composition of the glaze. In the past, when it was called white jade, it was added in small quantities to glazes as a flux or used as the main ingredient in soft-fired glazes for low-temperature firing, and there were only a few types of it. In recent years, the use of frit-based glazes has become popular for ceramics and porcelain industrial products that are glazed at temperatures below 1200°C, and there are many types on the market for various purposes. The basic method of use is to add clay or sizing agent to the frit, which is the simplest form, but there are also forms in which feldspar and silica stone are added, and lime and zinc oxide are also added.
In addition to the frit for ceramics described here, frit for cloisonné enamel ware and frit for enamel ware are also made to suit each purpose.