Working with foam

[Herc Driver]

A utility knife works well...but I've found a carpet knife works better if you happen to have one around. The blade is slightly thinner and very, very sharp. Held at about a 30 or so degree angle from TDC, it will easily slice through foam board. It works best when cutting "with" the material and not across it, at a slow pace. The foam board tends to bunch up when you go too fast.