Cutting strip is used to protect the cutter under the blade. This cutlist should be replaced as needed. In order for the knife not to damage or scratch if the plotter runs out of foil. The shelf list is mounted on the cutting plotter at the time of purchase, but in use it may be damaged or worn and should be replaced. There must be no marks or tracks in your cutlist, if this is the case, we recommend replacing it with a new one to get a smooth and accurate cut throughout your foil.