Cutting insulation cleanly used to be like cutting your airline chicken dinner with a TSA-approved knife. . . not fun, not effective. I recently had a small insulation install that included cutting angles in the insulation batts. I decided to give Cepco Tools’ Insul-knife a shot. Insul-knife is designed to cut sponge foam, insulation batts, and pipe insulation. It can also be used to trim insulation around doors and windows. I used a scrap of plywood to compress the batt before cleanly cutting through the insulation. Worked like a charm, with nice, smooth cuts. Beware, the blade is sharp and the manufacturer recommends gloves be worn when handling the tool. I ordered mine from the friendly folks at SoundAway.com for about $35. More details also available at Cepco Tools.