Ferro Frit 3124.  Manufactured by Ferro, this borosilicate frit is high in calcium. It melts at very low temperatures and is 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). 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 3110. 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.
 
Melting range approx. 870-950C (1600-1750F)