The Complete Handbook of Vehicle Magnets

Chapter 1: Understanding Vehicle Magnets

The Physical Reality of a Flexible Magnet

A vehicle magnet, at its most basic, is a flexible sheet of rubber that has been permanently magnetized. But this simple description hides a complex piece of engineering that must perform a delicate balancing act. It must be strong enough to hold a graphic in place against wind, vibration, and the slipstream of a vehicle moving at 65 miles per hour, yet it must be weak enough to be removed by a person without tools and without leaving a mark on the paint beneath. It must conform to the curved panels of a door or a tailgate, yet be stiff enough to resist the force of a hand being dragged across its surface. Understanding these competing requirements is the foundation for knowing how to choose, use, and maintain a vehicle magnet.

The structure of a vehicle magnet breaks down into two primary components: the flexible magnetic material itself, often referred to as "magnetic rubber" or "magnetic sheeting," and the graphic layer applied to its outer face. The magnetic sheeting is the workhorse. It is a composite material, typically made by mixing a ferrite powder—a form of iron oxide—with a polymer binder such as PVC or a rubber compound. This mixture is heated and extruded into a thin, flat sheet. While still pliable, the sheet is passed through a strong magnetic field, which aligns the magnetic domains within the ferrite particles. The sheet is then cooled, locking the binder