To break out a score, hold the glass firmly near the score line with the flat jaw up. Use your free hand to hold the other side of the glass and bend downward to break the score.

To groze, hold the pliers curved side up, using a rolling motion to gently scrape the glass edge against the serrated teeth. Use the tips in a chewing motion to nibble glass away, including deep inside curves.

Running pliers let you break difficult scores with ease. The curved jaw applies equal pressure to both sides of the score line, causing the score to "run". There is an adjustment screw for adjusting to the glass thickness. More pressure runs a score more quickly. Start out by running the score slowly from one end to about half way, and then from the other end until the runs meet.