Melt fluidity and coverage: RedArt Slip vs. Albany Slip vs. Alberta Slip
These three melt flows and mugs were fired at cone 6 (using the C6DHSCfiring schedule). The benchmark recipe is 80% clay and 20% Ferro Frit 3195. The center melt flow and mug (made from a Plainsman 3D-based stoneware) employs original Albany Slip as the clay portion. The one on the far left uses an Albany Slip substitute that was developed by calculating a mix of RedArt and other materials to have the same chemistry as Albany Slip. The one on the right employs Alberta Slip. Notice that, although the Alberta Slip version has a very similar melt flow, on the mug it is apparent that it needs a little iron oxide for a better match (e.g. 1-2%). And the glaze on the left: The chemistry of RedArt is different enough from Albany that some compromises in chemistry-matching were needed to avoid over-supplying the iron even more (and firing even darker than this). Although this Redart version runs in a very similar pattern on the melt flow, the character of the glaze is somewhat different on the mug (a better match can be achieved by increasing the frit percentage slightly, or firing to cone 7).