Spectrum's 500 Series Underglazes are all lead free, dinnerware safe, and A/P non-toxic when covered with a clear glaze. Underglazes can be used at almost any temperature range and can be applied to bisque or raw clay. Two to three coats are required for opaque, vibrant colours. The samples shown are at Cone 05, but these underglazes can be fired from low-temperature (Cone 06/04) to high-temperature (Cone 9/10). Some variation in colour will occur at higher temperatures and also different clear coats and thicknesses can affect the hue of each underglaze.