Glass Glitters are extremely brittle! I usually defer to pros like Precision Drum Co or Jammin Sam to precut the material to the sizes that I need. It saves a lot of headache. If you already bought the sheets of wrap though, I would suggest scoring the wrap with a utility knife (fresh blade)several times to create a starter groove. These wraps are tough! The crushed glass underneath the clear coat is very tough to cut cleanly.