nice argument, but just doesn't hold up ... Mylar IS much more reflective than foil (and, the 'transparency' of it doesn't matter, as it is normally placed upon a wall, or sheet of plywood, etc.) ... and I know this, by measuring the reflected light with my light meter (hand-held photographers spot-meter) ... flat white is second place behind Mylar, foil is WAY down the list ... :smokin: