How to protect copper from dimming

  I like to work with copper. It's absolutely wonderful metal. And especially I like its gentle pink color, like the color of human skin. But the copper dims quickly on the air without special protection.
And I have one advice how to avoid this.

After careful polishing with polish paste or pillows, I use a special Maas metal polish cream.

 Apply a bit of cream on a dry cloth and rub the copper. Wash the jewelry with warm water and soap.

But this is not enough. I put 2 layers of special metal lacquer Rustins on the copper. The second layer should be applied 4-8 hours after the first. Now your copper jewelry is securely protected.