Outdoor & Car Magnets 30 Mil Square Corners will give you all perks that an outdoor custom rectangle magnet can offer. To make the most of these custom rectangle magnets you have to do two things, first of all ensure that all your important brand information is included and secondly check whether you are getting access to full-color printing. We will ensure both these elements and that too for free. These custom magnets are also UV safe and fade resistant.