Clearly you haven't either A) actually tried that method of cutting foam; or B), needed to cut foam to a precise straight edge, of consistent thickness, shape, and geometric dimensions. It's much more difficult than most people think. As well, even the straightest of cuts requires the sharpest of blade edges. Add in the fact that the denser foam being cut, the faster deterioration of a scalpel sharp edge doing the actual cutting. That means you'd better have a stack of razor sharp blades, OR, acquire, devise, build, barter for, or buy yourself a hotwire foam cutter. Dont just take my word for it. Put it to the test and let me know what your conclusion is.
