After printing a high resolution image, the manufacturer then laminates the picture and pulls it around all 4 edges of a hard cardboard backing. It is then glued down on the back where it meets a hard magnet which covers about 95% of its back. The edges are all rounded for a smooth feel, and because of all the material, the magnet should sit about 1/8-1/4 of an inch off any surface. Magnet measures 3.5 x 2.5 inches. They are sturdily constructed and should last for many years as long as they are kept away from extreme temperatures and direct sunlight.