Sizzix Big Shot Pro Accessory - Mylar Shims, Standard, Set of 2
Big Shot Pro Mylar Shims are used to compensate for minute variations in paper thicknesses and wear on the Cutting or Crease Pad. If the steel rule of the die fails to cut the shape completely, use one to two Mylar Shims.  Both Mylar Shims measure 0.10 mm thick.