Sure thing. Keep the paintbrush look tight—no extra weight. Use a thin fiber‑optic laser that's fed from a small battery pack hidden in the handle. The tip can be a sharpened tip that looks like a brush bristle, but when you tilt it you get a narrow beam. Shield the laser with a heat‑resistant paint finish so it doesn’t leave a mark when you paint. Store the power pack in the bristle holder so it looks like a storage compartment. When you need to cut, just pull the bristles apart and the laser fires. That way it still looks like a brush but you can slice through steel when you’re under cover.