Ingredients

Ingredient Amount
Whiting 5.00
Calcium Borate Frit 39.00
Soda Feldspar 27.00
China Clay 6.00
Silica 23.00
Add Amount
Chromium Oxide 0.20

Instructions

Excerpted from the book Colour in Glazes, by Linda Bloomfield.
Calcium borate frit is an English frit similar in composition to colemanite with some added silica. American frits such as Ferro 3124, 3134, or 3195 can be substituted but they contain less boron and more silica. 'Borax frit' contains sodium, calcium, and boron similar to Gerstley borate and can be substituted with Ferro 3124 or 3134.