A flat surface formed by man-made polymers used to protect surfaces below it from nicks and cuts from a rotary cutter or Exacto knife. These are sometimes referred to as “Self-healing Cutting Mats” because the polymer will close back up after it is cut, but over time the surface will eventually degrade and need to be replaced.  Most mats are printed with grids at 1″ increments and other markings to aid in measurement.