First of all, cut a square of the copper sheeting so that it is about 6-8 in. square in size. It is much easier to do this with a metal guillotine; however, if you haven’t got access to this sort of equipment, tin snips will work just fine.
When you have done this, wash your hands thoroughly and dry them. You need to remove any grease or oil from your hands that could cause problems with the next step of the process. Remove any grease or detritus from the copper sheeting. Next, take a piece of emery cloth, and thoroughly sand down the piece of copper on both sides to remove the top layer of oxidized copper.
This will leave you with nice bright shiny red copper underneath.
You now need to heat treat the copper, in order to form an oxide coating on top. It may sound counterintuitive that we have just removed all the oxide and now we are going to put oxide back on, but the oxide coating we will be applying will be a film of “cuprous oxide.”
You will need an electric hob to do this. If you have any “heat proof goves” and metal tongs, this might be the time to get them in order to handle the metal while hot.
You need to turn the burner to the highest setting, with the sheet of copper just placed on top. Observe the changes to the copper carefully, they are very interesting.
As you heat the copper, it takes on a lovely vivid patina of different colors.
