This is 100% Alberta Slip (outside) on a buff stoneware (left) and iron stoneware (right) fired to cone 10R. The glaze is made using a blend of roast and raw (as instructed at the PlainsmanClays.com product page). Alberta Slip was originally formulated during the 1980s (using Insight software) as a chemical duplicate of Albany Slip. The inside: G2947U transparent. The intensity of the color depends on firing, add a little iron oxide (e.g. 1%) if needed.
GA10-A - Alberta Slip Base Cone 10R
Alberta Slip at 60:40 calcine:raw makes a great tenmoku-like glaze at cone 10R
Duplicating Albany Slip
How Alberta Slip was created by analysing and duplicating the physical and chemical properties of Albany Slip
Alberta Slip, 20 Years of Substitution for Albany Slip
Alberta Slip makes a great base for glazes because not only is it almost a complete glaze by itself but it has low thermal expansion, it works well with frits and slurry properties can be adjusted.
Calcining is simply firing a ceramic material to create a powder of new physical properties. Often it is done to kill the plasticity or burn away the hydrates, carbonates, sulfates of a clay or refractory material.