Simulated patina for copper

A process for imparting a simulated patina appearance to a copper substrate, and a substrate having that appearance. A colorant having the desired initial patina color tone is employed to produce a non-continuous layer of colorant on the surface of a copper substrate. The appearance of patination of the desired tone is created by interspersed spots of colorant with the remaining portion of the substrate being exposed for natural patination. The interspersed spots of colorant may be produced by screen printing, by spattering, as by spraying, or by mechanical removal of colorant after application to the substrate surface, or a combination. The colorant is preferably a paint and may be applied by non-uniform spraying on the substrate surface. Non-uniformity may be accomplished by varying the volume of colorant sprayed during the application process or by varying the relative movement of the spray and substrate. After application, the colorant provides a simulated patina to the copper substrate surface while allowing the remaining (non-covered) portion of the substrate to patinate naturally.