these are the tests of potash feldspar and calcium carbonate, in 100%, 25%/75%, 50%/50%, 75%/25%, 100% quantities. we fire it to see what happens.
below is the 5 different clays we made up. they got weighed and have 100mm lines to test for weight loss (water content) and shrinkage during firing. we test at bisque (980 C) and then again after stoneware firings (1300 C)