Spectrum's 500 Series underglazes can be applied on greenware or bisque, and they can be used with or without a clear glaze covering.
When used without a clear glaze cover, they have a matte velvet like surface, but they are not considered dinnerware safe.
They are opaque with 3 coats, semi-opaque with 2 coats and semi-transparent with 1 coat. They are compatible for use under most clear glazes.
They can be intermixed to create your own colors. However, we recommend not mixing 561, 562, 563, 567, 568, 569 with any of the other colors. These colors are based on cadmium encapsulated stains that do not mix well with other ceramic stain colors.
Spectrum underglazes generally have good temperature stability up to cone 6, and for many colors to cone 10. When fired hotter than cone 04, you may get small color variations from those shown on our charts, so please test them for your application.
All Spectrum underglaze colors are lead-free, A/P non-toxic and dinnerware safe when covered with a dinnerware safe clear glaze.