Custom flat magnet with custom corners. 5 Sq Custom flat flexible magnet with custom corners.Create flat, flexible magnets in any shape through three easy steps. First, create your shape and message. Then, send us your artwork, message and specifications. Lastly, we'll produce the custom-shaped magnet by your specifications. There's free tooling and no additional tooling, set-up, or die charge for generalized shape. At approximately 0.020 in total thickness, the magnets feature a wide range of options!