I am working with a terra cotta clay right now and found this transparent cone 04 clear. You can also add colorants. I have found 40%, 30%, 30% glaze recipes to be very stable. This recipe fits that format.
Deb’s Clear Base Cone 04
Ferro Frit 3195 45%
Ferro Frit 3134 30 %
EPK Kaolin 25 %
Butter Yellow:Add: Mason Stain 6464 2%
Moss (food safe): Add: Copper Carbonate 2. 5 % Burnt Umber 4 %
This glaze is transparent and shiny Apply thin in order to ensure the glaze will be a transparent clear It is very responsive to colorants Use a thicker application with colorants to achieve a rich translucent glaze From
Joan Bruneau, Pottery Making Illustrated, Nov/Dec 2010.