Red is a vivid crimson at cone 05/06 that deepens to a dark, wine red at cone 5/6 and becomes brown and starts to burn out at cone 10. A clear glaze will accentuate the glaze nicely at cone 05/06 and 5/6. At cone 10 the clear glaze will burn out some of the red color.
Tableware producers must test all finished ware to establish dinnerware status, due to possible variations in firing temperature and contamination.