Just an after-thought on this process, one prompted by Donald Gilles recent contri.
Donald was bang-on when he said that the quality of the shine on a copper-plate depends on the quality of the finish of the substrate, and that any polish - all of which contain some abrasive - will to extent leave minute lines on a finish.
I wonder that if you know that your frame is actually copper-plated and not copper flam paint whether it would be worthwhile, before attempting to remove any oxydisation by polishing, to gently clean the area with a chiffon rag, or similar dipped in Coca-Cola - a product that I assume is readily available in the States. For that matter some fruit juices have the same effect of removing surface discolourisation when applied to coins..and little pieces of jewellery. As for the final polish, if needed, I think I would try the finest - in terms of grain size - jewellers rouge. This works extremely well on silver and nickel, and might work on copper.
Norris Lockley
Settle, UK
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