Barium is used as a flux in glazes and clays to enhance colour, and also in small amounts to prevent scumming from soluble salts in clay. Josiah Wedgwood used barium sulphate in his Jasperware coloured clay body. Potters nowadays more often use barium carbonate as the sulphate gives off sulphur dioxide gas during firing.
Barium carbonate can be used to make brightly coloured
