Radiant Red Velvet Underglaze is a bright scarlet color that is vivid at cone 05, deepens at cone 5, and becomes slightly glossy and a deep fire-engine red at cone 10. A clear glaze accentuates the underglaze significantly at any temperature. For Radiant Red Velvet Underglaze, we recommend using HF-10 Clear. HF-9 Zinc-Free Clear is recommended for use with underglazes to reduce the incidence of color shift. Most underglazes, stains, and coloring oxides will show their best color with Zinc-Free Clear.