Left: Cornwall plus 10% Ferro Frit 3134. Right: Nepheline Syenite plus 10% of the same frit. These are fired at cone 6.
Nepheline Syenite is a type of feldspar. We use it in porcelain bodies. The nepheline content determines the temperature at which the body is vitreous. We use this product in preference, where possible over soda or potash feldspar. There are several reasons: It is mined and processed in Canada and is renowned around the world for it's quality. If has a very low iron content, this makes for whiter-burning bodies. It is a more powerful flux than common feldspars. It has been very consistent over many decades.