Here it is fired to cone 8 where the melt obviously has much more fluidity! The photo does not do justice to the variegation and crystallization happening on this surface. Of course it is running alot more, so caution will be needed.
GR6-M - Ravenscrag Cone 6 Floating Blue
Plainsman Cone 6 Ravenscrag Slip based version of the popular floating blue recipe.
A popular cone 6 glaze that employed Gerstley Borate, it was very troublesome to use and to fire. Much work has been done to create alternative recipes.
In ceramics, reactive glazes have variegated surfaces that are a product of more melt fluidity and the presence of opacifiers, crystallizers and phase changers.
Ceramic glazes melt and flow according to their chemistry, particle size and mineralogy. Observing and measuring the nature and amount of flow is important in understanding them.