GR6-M Ravenscrag cone 6 Floating Blue (center) on Plainsman M340, a buff burning body. On the left is a version having 80:20 Ravenscrag:Frit 3134 (no extra 10% Frit 3124). On the right is GR6-M on porcelain (where the floating effect has been largely lost). It appears the effect benefits from the iron it finds (albeit not much) in the stoneware body.
GR6-M - Ravenscrag Cone 6 Floating Blue
Plainsman Cone 6 Ravenscrag Slip based version of the popular floating blue recipe. It can be found among others at http://ravenscrag.com.
G2587 - Floating Blue Cone 5-6 Original Glaze Recipe
Floating Blue is a classic cone 6 pottery glaze recipe from David Shaner. Because of the high Gerstley Borate content it is troublesome, difficult. But there are alternatives.