Mayco Foundations Opaque Glaze - FN 019 - Dark Blue - 4 Ounce Jar Broad palette of colors that produce a beautiful, smooth high gloss finish and can be intermixed for custom colors. Foundations glazes dries quickly, allowing immediate additional decorating and same day firing. Foundations Opaque glazes can be fired to higher temperatures. Check individual color label for cone 6 results. Certified AP non-toxic and food safe. Made in USA.