The ceramic coloring compounds are used like water colors for shading and details. They are applied to the surface of enamel, window or stained glass. The underlying enamel/glass will be stained by firing. Since these are highly pigmented powders, they are used in thin, film-like layers. They are not an enamel in themselves. They should be covered with a transparent enamel or the finish firing. Sold in 20 gram amounts per pigment. Can be mixed with Painting Flux or Mixing White.