Both have been applied at moderate thickness on Plainsman M325 (using a slurry of about 1.43-1.45 specific gravity, higher values end up getting them on too thick). The Ravenscrag version highlights contours better (the edges are black because of the black engobe underneath). It also produces the blue color whether or not the kiln is slow cooled to 1400F (although a faster cool is less blue). But the Alberta Slip version has zero cobalt so is less expensive to make. It produces a deeper color over the black engobe underneath the upper section of the pieces. Both of these produce a wide range of effects with different thickness, bodies and firing schedules.
GA6-C - Alberta Slip Rutile Blue Cone 6
Plainsman Cone 6 Alberta Slip based glaze the fires bright blue but with zero cobalt.
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.