They will delaminate somewhat during bisque, Handle joins will crack somewhat during drying. They are splitting at the rim during throwing. The glazes will craze on all of them. But the extent and manner in which these things happen will enable me to compare them. These are kaolins (mixed with feldspar) to vitrify around cone 6. I am comparing current shipments with previous ones. This demonstrates the value of a potters wheel in directly judging absolute and comparative plasticities and drying properties and providing specimens to testing glaze fit and coverage.