What is "tin-glazing"

Tin-glazing is the process of giving ceramic items a tin-based glaze which is white, glossy and opaque, normally applied to red or buff earthenware. The opacity and whiteness of tin glaze encourage its frequent decoration with colour.

Tin oxide is valued in glazes as both an opacifier and as a white colorant. Tin oxide has long been used to produce a white, opaque and glossy glaze. As well as an opacifying agent, tin oxide also finds use as a colour stabiliser in some pigments and glazes. Minor quantities are also used in the conducting phases in some electrical porcelain glazes.