glazeandpigment

Glaze and pigment are two foundational terms in ceramics and visual arts. Glaze denotes a vitreous coating fused to a ceramic surface during firing, often forming a glossy, glassy layer that seals the surface. Pigment refers to finely ground colorants used to impart color in paints, inks, ceramics, and glazes.

In ceramics, glaze ingredients include silica, alumina, fluxes, and stabilizers. When heated, the glaze melts and forms a glassy layer that can be transparent, translucent, or opaque. The surface finish is influenced by glazing temperature, flux composition, and firing atmosphere; color in glazes is created by metal oxide pigments or stains added to the glaze body.

Pigments used in ceramics range from inorganic oxides such as iron oxide, cobalt oxide, chromium oxide, manganese, copper, and titanium or zirconium-based pigments to organic pigments. They can be used as stains mixed into the glaze, or as underglaze colors applied before a clear glaze, or as overglaze enamels after the body has been fired.

Compatibility is key: pigments must withstand melting and not devitrify; some pigments may migrate or cause pinholes if not properly fritted. Techniques include dipping or spraying glaze, applying underglazes, or applying stains to engobes. In painting, glaze refers to a transparent layer of medium laid over dry color to alter hue and depth.

History and safety: glazes have ancient roots across many cultures, including tin-glazed ware and alkaline glazes. Modern practice relies on fritted glazes to reduce hazards such as lead release; safety considerations include proper ventilation, testing, and compliance with regulations governing toxic pigments and glaze materials.