Has anyone had experience with active packaging in microwaveable food products?  Other than cooking lunchtime snacks, of course!  Some of the more common tradenames are qwik crisp, quilt wave, etc.  I was wondering what the material is that is laminated to the paperboard, if it is a metal foil, metallized mylar, or if it is a proprietary trade secret.  Ideas anyone?  Yes, I know there are numerous companies that supply this packaging, but that doesn't satisfy my curiosity to know what the stuff is.