The Z-Blade scalpel-knife is the best tool we have found for cutting foam for fly tying. Razor sharp, durable and much easier to control than a razor blade. Medical stainless steel, durable, yet inexpensive. You will find tons of other uses for these scalpels as well. SOLD IN PAIRS- $9.99.
Z-Blade Foam Cutter
Scalpel-Knife foam cutter (pair)
Sold in pairs, 2 knives for $9.99