Sax Fern underglaze paint comes in a concentrated opaque liquid color. Decorate pottery with this glazing paint that's ready for use on clay, greenware, and bisque. The color may be a different shade during application and will change to the desired look after the required kiln firing. This painting medium's color slightly darkens when fired at cone 6. Our high-quality underglaze has a matte look after firing and can be transformed to a shiny, rich glaze appearance with a transparent glaze coating on top. Download Sax True Flow Glaze Care Tips