Miriam's Cone 10 Glaze: a variation on Val Cushing's Wild Wonder

Gerstley Borate         48

Talc                    22

Titanium Dioxide        14

Zinc Oxide              10

Lithium Carbonate       6

Black Copper Oxide      2

To make the glaze on this tile, I added 2% black copper oxide to a recipe from Val Cushing’s Handbook.  Cushing recommends this glaze for reduction firings, but after testing it with a variety of colorants, I found all of the results more interesting in oxidation.  The gerstley borate and titanium dioxide in this glaze give it a highly active surface, with streaks of pink and cream.  The addition of black copper oxide gives it a bit of a metallic sheen, and adds greens and grays.  This glaze is quite runny, but it can be stabilized by reducing the gerstley borate to 43% and adding 5% silica.  This will make the glaze less drippy, but will also result in a slight loss of texture.