Potterycrafts Colemanite Flux

Colemanite is a naturally occurring source of Boron. A powerful primary or secondary flux 4.5% SiO2 in glazes. It intensifies the effect of colouring oxides and increases craze resistance of glazes. P2954 (Calcium Borate Frit) may be used as an alternative.

• 43.9% B2O3
• 26% CaO
• 4.5% SiO2