I just cut several pieces and at the merchants suggestion I:

1) Scored it, with pretty firm pressure, 8 to 10 times with a box knife.
2) Hung the cutoff area over the edge of the bench with the score at bench
edge. Place a rigid straightedge or board, also even with the score and
bench-edge, and held or clamped firmly.
3) Pushed the cuttof down smartly and quickly.

Most of the cuts came out looking pretty good. I did have to dress a couple
of areas with sandpaper. This was with 1/8" material.