Ferro Frit 3134

1000-1150oC 9.6 Expansion SiO2 46.5%, B2O3 23.1%, Na2O3 10.3%, CaO 20.1%
Similar to 3124 but higher in boron and calcium with no alumina. The low alumina is useful as it allows you to use more clay in a glaze. It can be added to a glaze without having to reduce the clay content.