Hey There - These days using silver and gold alternatives and working in mixed media is a must, not just "trendy". But, there are a lot of questions from those of us who have decided to mix our metals and change things up a bit.
When I was asked a question about preserving patinas on copper I nearly froze. I thought I had the solution but just wasn't sure. I would use a microcrystalline wax (Renaissance Wax to be precise). And, if I were at an art show I would tag the piece with the appropriate suggestions for their upkeep.
Because of my temporary temperature drop I decided to do a little investigating and ran across a forum for copper wire workers. Well, why not check with what they suggest? It never hurts to "google" up some answers. Whew, I feel better. Add this one to your resource list: