Several years ago I read an article by Bill Helwig on Plique a Jour using copper sheet and a backing of copper foil. Not until recently did I find the time to experiment with the art of plique a jour and remembered this article to review as I began my exploration. I could remember him saying enamels do not adhere to copper. This is why you can use copper as a backing and peel it off after you are finished.
At this time this link had here is not working. Glass on Metal is no longer being published. I will try to get hold of this publication and post it here. Stay tuned!
One of the wonderful properties of copper and enamels is the warm qualities it give the enamel! In image one he has cut out the copper sheet and in image two he has secured the copper foil to the back of his design. From here he has filled the cells and fired to the point of completion and of course there is fire scale to deal with but he has created a beautiful piece!
Plique a Jour by Bill Helwig
More plique a jour,