AMACO Potter's Choice Glazes - Lead Free Cone 5-6. This si a collection of potters' favorite glazes made easy. These glazes are fired in an oxidation kiln and have the look of Cone 10 reduction glazes without a gas kiln. PC-50 needs to be applied irregularly. Apply two irregular coats. Once you have used it a while you will see the effects that can get by varying the application.