Based on Tony Hansen's 20x5 transparent glaze Hansen 20x5 with 7% Tin Oxide addition for a white opaque.
This is probably too white for my taste, need to experiment with a lower percentage addition of Tin.
| Material | Ratio | 
| Potash Feldspar | 20 % | 
| Flint | 20 % | 
| Frit 3134 | 20 % | 
| Wollastonite | 20 % | 
| Grolleg | 20 % | 
| Tin Oxide | 7 % | 
| Bentonite | 2 % |