Blue Slips for Wood Firing

I tried 2 new blue slip recipes, as my previous experiments were not blue enough.

Blue Slip 1:
60 Hymod AT
20 Potash Feldspar
10 Talcum
10 Flint
2 Cobalt Carbonate
2 Copper Carbonate

Blue Slip 2:
60 Hyplas 71
20 Potash Feldspar
20 Silica
0,5 Cobalt Carbonate
2 Iron Oxide

• Iron Oxide is not really helpful as it tends to oxidize back to brown if reduction is not strong enough.
• Cobalt Carbonate can cause black areas, eventually only if applied too thin.
• Salt preserves the blue color during cooling, but also results in higher glaze flow.