Leadless high calcium borosilicate frit. This is a USA pottery frit.
This borosilicate frit is high in calcium. It melts are very low temperatures and among the most useful of all common frits because of its glaze-like balanced chemistry. This frit has a chemistry somewhat similar to 3134 (the latter adds CaO, Na2O and B2O3 at the expense of all the Al2O3 and some SiO2.
Its stated intention is a calcium boron source for partially fritted glazes for wall tile and pottery, also in lead bisilicate dinnerware glazes in the cone 3-5 range. However, within pottery circles, like frit 3195 this frit is almost a complete glaze at low temperatures (requiring only a 10-20% addition of kaolin to suspend it).
It has a medium thermal expansion and fits most bodies. However, if glazes shiver some of this can be traded for Frit 4110. If they craze some can be substituted for Frit 3249. Frit 3124 is often added to glazes to make them melt lower, this works well because it is quite balanced already as a glaze, the net effect of adding it is to increase the boron content without overly disrupting the balance of other oxides.
Since the chemistry is high in CaO, it will affect browns and iron oxide colours.
A frit is a type of ceramic glass. It is a combination of materials that, when melted together, are rendered insoluble and resistant to acid attack. They are, therefore, a means of introducing certain materials into a glaze which would otherwise be toxic. Frits can be used alone as low temperature glazes, e.g. raku and majolica, but generally they form the basis of a glaze recipe.
Replaces Frit 4124