Clear glaze for terracotta, Medieval tiles

[Martin Webb]

I need a clear glaze for some terracotta floor tiles, I'm making replica Medieval tiles with inlayed white/buff clay and want a clear glaze that keeps the red clay lighter and red rather than turning it dark brown. I know it is linked to the temperature and a lower glaze firing is better but it would be good if anyone knows of a type of glaze that is better for this? I know they used Galena in medieval times which gives a wonderful warm red colour but obviously need a practical alternative!  

[Min]

A lot of years ago I used a version of Deb's Clear, there is a newer revised version of it below (added silica). Don't know if you have access to both those frits in the Deb's Clear in the UK? One that I would try is this one from Glazy, note the drop and hold firing schedule to clear bubbles. Glazy recipe uses Gerstley Borate. Both are high boron recipes, you will have to test to see if they fit your claybody as well as for colour.

Deb's Clear Revised ^04

Ferro Frit 3134      29.13

Ferro Frit 3195      43.69

EPK Kaolin               24.27

Silica                              2.91