This Magnetic Shim is made of special materials to reduce crinkles in long term use. It has scales in inches and centimeters to help you locate dies in correct positions. Simply sandwich the die and material to be cut between the cutting pads and roll through the machine. Note: This Magnetic Shim is subject to wear and tear. To care for your plates, please flip and rotate after each pass. If the plate does start to bow, flip over and pass through until it is flat again, then continue to flip and rotate as normal.