But it can be done. The
But it can be done. The copper needs to be thin. It works best if you clean the copper, and then coat it with borax. It has to be done with a long soak to ensure the bottom of the glass is as soft as the top. You have to protect your shelf from contamination by the copper sheet. Not all attempts will be successful, showing that this is on the edge of acceptability.
It is easier simply to glue the copper to the back.