Our best protection for labels, Bar Codes, Spine Labels or Patron Cards. 5-mil, acid free, extra heavy-duty vinyl stretches to conform to book spines or media. Matte finish protects labels from dust, dirt, smudges, scratches, fingerprints and peeling. Keeps bar codes clean and easy to scan. Rounded corners prevent lifting and edges from curling. Superior adhesive becomes permanent after a few hours, is acid free and will not yellow or crack with age.