The mylar in the cardboard holder didn't cause the damage you show, Jill. There's no way chemically to absorb or vaporize chunks of plastic to result in the ragged edge you show.

By the way, the only 'flip' in your scan is the empty one in the center. The others are cardboard holders with mylar windows. A common terminology mistake, but only flips have a hinge between two sides so you can 'flip' them open.