As a fused glass coating, porcelain enamel has long been used to protect metal substrates from chemical attack, abrasion, and other corrosive and mechanical damage while also serving a decorative function. While a wide color and gloss range has been possible using traditional oxide pigments and other additives, it has not been possible to formulate enamel with an appearance similar to uncoated aluminum or stainless steel. Unfortunately for frit suppliers, this has left stainless steel as a major viable alternative to an enameled surface. Generally, the only vitreous metallic finishes have been achieved using pearlescent pigments. These are flakes of mica coated with titanium dioxide or some other type of surface modification. While these can provide a sparkle appearance, they do not have the opacity of metallic pigments. Organic fluoropolymer and silicone coatings with a metallic appearance are commercially available, but, relative to porcelain enamels, these have poor mechanical and thermal properties. Using new additive technology, enamels with a true metallic appearance have been developed that can be applied to aluminum, aluminized steel, or steel. These have the performance of vitreous enamel while having an aesthetically pleasing bright metallic finish. The metallic look can be used to break up the uniform shades of black and white that have been very common on porcelainized surfaces.
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