Tin(IV) oxide has long been used as an opacifier and as a white colorant in ceramic glazes.The Glazers Book – 2nd edition. A.B.Searle.The Technical Press Limited.' London. 1935. This has probably led to the discovery of the pigment lead-tin-yellow, which was produced using tin(IV) oxide as a compound. The use of tin(IV) oxide has been particularly common in glazes for earthenware, sanitaryware and wall tiles; see the articles tin-glazing and Tin-glazed pottery. Tin oxide remains in suspension in vitreous matrix of the fired glazes, and, with its high refractive index being sufficiently different from the matrix, light is scattered, and hence increases the opacity of the glaze. The degree of dissolution increases with the firing temperature, and hence the extent of opacity diminishes. Although dependent on the other constituents the solubility of tin oxide in glaze melts is generally low. Its solubility is increased by NaO, KO and BO, and reduced by CaO, BaO, ZnO, AlO, and to a limited extent PbO.
SnO has been used as pigment in the manufacture of glasses, enamels and ceramic glazes. Pure SnO gives a milky white colour; other colours are achieved when mixed with other metallic oxides e.g. VO yellow; CrO pink; and SbO grey blue.