Magna-Seal Postcard - Custom Size (5 x 4.25 to 8.5 x 5.25). Magna-Seal laminated post card gives you extra impact in your direct mail (or bulk mail) marketing. Your magnet is laminated to the surface of the card, giving you the most convenient way to get your magnet & message into your customer's hands. Studies show that postcards with magnets attached are much more widely read than ordinary direct mailers. Includes up to 30 minutes of art setup time.