These mugs are fired at cone 6 with GA6-G1 Alberta Slip lithium brown. The difference: the ratio of raw to calcine Alberta Slip. In this glaze, a 50:50 ratio was not working well (left). The glaze was shrinking too much on drying, then crawling on firing (it needs to be thickly applied to get the visual effect I want). I mixed the recipe using pure calcine Alberta Slip, then repeated a cycle of pouring a little of this into the 50:50 mix and trying it. I kept doing that and glazing another mug until I had a minimum of drying cracks (while still having good gelling, application properties and dry hardness). The mug on the right was the last cycle, it has fired perfect. Using this technique I can perfect the ratio of raw:calcine for each Alberta Slip glaze I use.
GA6-G1 - Alberta Slip Lithium Brown Cone 6 Low Expansion
Plainsman Cone 6 Alberta Slip based glaze. It can be found among others at http://albertaslip.com.