Copper Etching

Decided to try out some copper etching using a 1:1 mix of vinegar and hydrogen peroxide. Used the stencil cutter from Tekbots to cut some vinyl to cover the copper that I wanted to keep. I also tried to use a Sharpie to protect the copper at the suggestion of a friend, but that did not seem to work. Important notes: the mixture needs to be stirred to remove build-up on the copper which will stop the etching process. I used a cheap battery powered drink mixer with my programmable power supply. The smell is terrible and should be done in a well ventilated area. When the reaction is complete the liquid becomes a strong blue color (no picture unfortunately). The new stainless steel nut I had in there to prop up the plate also got corroded, and it wouldn't be a good idea to pour this down your sink.