Many decorative paints and glazes are used to refine the surface of ceramic products such as earthenware, stoneware and porcelain. In addition to frits, the basic components of the paints and glazes are primarily special pigments.
These ceramic paints are usually inorganic compounds, mostly oxides, silicates, aluminates and metal borates. One can distinguish between underglaze colors, inglaze colors (as in-glaze and high-fire paint), and onglaze colors (enamel, enamel paint). Common ceramic colors are chrome green, cobalt blue, iron red, vanadium-zircon stains and zinc paint.
In contrast to the crystalline, porous base material, this type of surface decoration produces a glass-like, cohesive surface layer.
Ceramic pigments are usually finely ground in alcohol as the solvent in order to prevent oxidation and, with it, a reduction in quality. This places high demands on the design of the machines and the materials used to build them.