Cobalt Blue 500 Series Underglaze

Fired to cone 5 with no clear glaze over it, this colour starts to go glossy rather than staying matte. Spectrum builds the 500 series on a frit base instead of clay slip. That is why you can brush it on greenware or on bisque and fire it bare or under a clear glaze. Left bare it dries to a matte, velvet-like surface. Under a clear glaze the colour deepens. One coat is semi-transparent, two coats are semi-opaque and three are opaque. Spectrum rates it cone 06 to 6. It is dinnerware safe once a food-safe clear glaze is fired over it. Lead-free and AP non-toxic. Conforms to ASTM D-4236.