I recently replaced my storm door and used the aluminum framed windows for two posters of my own. I lightly sanded the aluminum and sprayed it with poly in a can. I backed it with waxed cardboard from a butcher shop (unused). and sealed it with duct tape, because they are hanging in the bathroom. A very techno look. As a bonus they're tempered in case a brawl breaks out in the loo. RScott