Copal is a natural resin medium historically used by the Flemish masters to achieve their strikingly brilliant, enamel-like glazes. Copal Painting Medium improves the flow of paint from the brush and speeds the drying rate for oil colors. And unlike damar, copal is solvent-resistant when dry, so it's perfect for clean lifts when glazing. Whites and pale colors blended with Copal Medium retain brightness and resist the staining that can occur from subsequent applications of color. Dark colors appear deeper, more vibrant, and retain a wet appearance after drying. Avoid overloading paint film with copal as this can cause excessive yellowing.
Richeson Mediums are tested in accordance to: ASTM D-4236 and bear safety labels to the standards issued by ACMI. While some Richeson mediums are AP approved non-toxic, certain mediums bear the CL label with safety warnings.