Spectrum 853 Cobalt Blue Raku Glaze

Spectrum 853 Cobalt Blue Raku Glaze produces deep cobalt blue with green and copper transitions that become more pronounced during post-firing reduction.

Spectrum Raku Cobalt Blue produces a deep cobalt blue that can transition into green and copper areas. The intensity of these shifts depends on the reduction process, so the surface may appear predominantly blue or develop a stronger metallic character.

Spectrum Raku Glazes

Spectrum Raku is a series of ready-to-use brush-on glazes formulated for raku firing. The manufacturer recommends applying 2-3 coats to bisque ware, allowing them to dry completely, and firing to 950°C. The hot ware is then transferred to a reduction container filled with combustible material such as sawdust, straw or dry leaves.

Raku firing results are inherently variable and depend on the clay body, glaze thickness, firing temperature, reduction material and the reduction process itself. To obtain effects similar to those shown on the samples, keep the ware in a reduction atmosphere for at least 20 minutes. A thinner glaze application can intensify metallic effects in many colors. Once fully cooled, the surface can be cleaned with water and a scouring pad to reveal the sheen and color more clearly.

Spectrum 853 Cobalt Blue Raku Glaze

• After reduction, the glaze produces cobalt blue with green and copper transitions.
• The manufacturer recommends applying 2-3 coats of glaze to bisque ware and allowing them to dry completely before firing.
• The glaze is intended for raku firing at 950°C.
• After firing, the ware requires post-firing reduction. For results similar to the samples, we recommend at least 20 minutes in a reduction atmosphere.
• The final result can vary depending on the clay body, glaze thickness and reduction process, so testing on a sample tile is recommended.
• The glaze is not intended for food-contact surfaces.