Car Signs Magnetic Signs Most magnetic signs leave our facility next day. Choose from a variety of templates. All of these magnetic sign templates are customizable! Change text, images, colors, fonts with on-line preview. One side of this magnet is a white vinyl surface, the other side is black magnet. The magnetic sheeting are 30 mil. thickness. Our durable magnets are easy to apply and remove. When properly cleaned and cared for, magnetic signs can last up to three years.