It looks and feels like the facings of this unlabeled, salvaged polyiso are paper, but I’m told they might be fiberglass. Does anyone know for sure? I’m wanting to glue radiant barrier to one of the facings, and I need advice about what kind of roll-on glue to use and whether to use ordinary aluminum foil or a different radiant barrier product. I’ve never seen a self-adhesive radiant barrier, but if you have, I’m interested in that too.