how do you cut foam

Here is the Ceramic Utility knife I use......
slice.jpg
Absolutely agree on the ceramic, even a low end kitchen knife worked amazingly well. I lay the Airgun on top of the foam and then used thin painters tape to outline, then used marker to trace which made it easy to fix anything that I wanted to snug up a bit.
Had very bad results with a hot knife off Amazon for thicker foam but I guess you get what you pay for.
Also no ventilation needed when using a kitchen knife!