PC70 Copper RedCOPPER RED PC 70 Product Description PC 70 Copper Red is an oxblood red that gives the same results in oxidation as a traditional reduction copper glaze. Copper Red breaks clear on edges or where thin. Apply 3 coats for best results, do not thin glaze. CONE 5 6 Safety Warning Tableware producers must test all finished ware to establish dinnerware status, due to possible variations in firing temperature and contamination.