Creaser /(kr?s"?r)/

Creas·er

Creaser

n.
  1. A tool, or a sewing-machine attachment, for making lines or creases on leather or cloth, as guides to sew by.
  2. A tool for making creases or beads, as in sheet iron, or for rounding small tubes.
  3. A tool for making the band impression distinct on the back. (Bookbinding)