Cone 6: Copper Float glaze is a rich and complex midrange glaze with hues varying from reds, to coppers to gun metal blacks. Predominate coloration is a dark rusty red. The surface is satin-matte when fired to cone 5 or 6.
Cone 10: Finish flattens. Color changes to a warm brown with some copper mottling.
*The first image is cone 6 and the second image is cone 10.
Tableware producers must test all finished ware to establish dinnerware status, due to possible variations in firing temperature and contamination.