Mayco Foundations Opaque glazes form a broad palette of colors that produce a smooth, high gloss finish that can be intermixed to create custom colors. Foundations glazes dry quickly, allowing quick decoration and same day firing. Foundations can be applied to greenware or leatherhard clay when an area is allowed to remain unglazed for out-gassing during firing. Many Foundations Opaque glazes can be fired to higher temperatures and retain their color. Check the individual color label for cone 6 results. Certified AP non-toxic and food safe.