Along with the rusted paper, I have been busy "brewing" copper with ammonia to get a very pretty blue patina. I got this technique from Metal Craft Discovery Workshop by Linda and Opie O'Brien (click on favorite books on right sidebar). Start with a large plastic container with a lid and a small plastic container that fits inside the large container (Picture 1). You will also need a rack to place over the small container - I used hardware cloth that I cut to fit in the big container (Picture 2). Fill the small container half way with ammonia. Place the small container inside the large container and place the rack over the small container (Picture 3). Next you will need salt water, metal (I used both copper and brass) and sand paper (Picture 4). Sand the metal (Picture 5). Rinse the metal with warm salt water (Picture 6). Place the metal on the rack (Picture 7). Sprinkle metal with salt - any kind of salt will do, I like kosher salt because of the size of the grain (Picture 8). Cover the container with a lid (Picture 9). Wait a few hours and uncover - I uncovered mine after 3 hours (Picture 10). Presto! Your metal will have a lovely blue patina. Let the metal dry and then coat with a clear acrylic. I have been using a clear matte spray for the copper mesh book project. Picture 11 shows some pieces I have done. The brass piece is in the top left corner, all of the other pieces are copper. I have been wanting to try this technique for months and was kind of intimidated by it. After doing it, I'm sorry that I didn't start sooner. It's fun, the results are cool and it makes you feel a little like a mad scientist. Have fun and let me know how your experiments turn out. I'm thinking that I want to try some pennies, some copper brads, some brass brads, and........ I could go on and on!