RM 3414 Borax Frit
Borax has very strong fluxing power (comparable to lead oxide).
RM 2268 Calcium Borate Frit
RM 2275 High Alkaline Frit
RM 2265 H.T. Borax Frit
RM 2261 Lead Bisilicate
RM 2262 Lead Sequisilicate
RM 3447-200 Molochite 200
Calcined china clay. Used as clay substitute to lower shrinkage of engobes etc.
What are frits?
They are made by melting mixes of raw materials in special kilns, then pouring the mix into water and finally grinding it into a fine powder. Although the fritting process is expensive there are many advantages to using frits in glazes, enamels, etc. To render soluble materials insoluble. To improve process safety of toxic metals. To reduce melting temperature and improve melt predictability. To avoid
volatilisation of unstable substance. To achieve oxide blends that is difficult or impossible with raw materials. Many glaze formulations cannot be achieved with insoluble raw materials. Improve the quality of decoration. Over and underglaze colours work better with frits than raw materials because the former are cleaner, less reactive, melt evenly, and have a more closely controlled chemistry. This means colours are brighter by virtue of compatible chemistry, by better glaze clarity. Edges of colours also tend to bleed less.
