Ceramic pigments, often referred to as ceramic stains, have vastly opened up the color possibilities for potters. And as we all know, adding color to your ceramic art can be a tricky proposition.
Ceramic Pigments - Testing and Safety
When using ceramic pigments alone or in combination with other pigments and/or oxides, you’ll need to test them with the frit, glaze, and slip bases you intend to use. A good starting point is either using some of the published recipes or using frits. Because pigments are expensive to manufacture, their cost is higher than that of ceramic oxides, but you’ll find most suppliers will sell ceramic pigments in quantities as small as ¼ pound.
Finally, safety is always an issue. Suppliers are required by law to provide a Material Data Safety Sheet (MSDS), and there are different precautions listed with each pigment or family of pigments. Make sure you read and follow the instructions listed in the MSDS for safe handling.
When used as underglazes, surfaces coming into contact with food must be covered by a food-safe transparent glaze, and glazes containing pigments should be tested for food use.