Ingredients

Ingredient Amount
Barium Carbonate 36.46
Nepheline Syenite 44.20
OM 4 Ball Clay 9.95
Flint 9.39
Add Amount
Copper Carbonate 3.00
Bentonite 2.00

Instructions

Originally found in CM, Jan. 1997, from George McCauley  (Could have been named something else)

Test tile in Coleman Porcelain fired in reduction
More purple when thin, more blue when thick