How do you make the surface of the copper copper board the surface color of the copper coin?
With some chemical acid, diluted after poured into the earth, and then put the coins buried in, about half of it, you can.
When the copper wire drawing drawing color shades become when you want to color you can put on the water rinse attention must complete color spray paint to light a good copper color
A bottle of anhydrous potassium hydroxide with anhydrous potassium sulphide to a large basin of water to the copper inside then became black and copper wire cloth
