A glass cutter is a tool used to score glass, making it easier to break along a straight line. It typically features a small, sharp wheel made of hardened steel or tungsten carbide that creates a shallow groove on the glass surface. This scoring weakens the glass, allowing it to be snapped cleanly along the line. Glass cutters come in various designs, including handheld models and those with a built-in oil reservoir for lubrication. They are commonly used in glassworking, construction, and arts and crafts. Proper technique is essential for achieving clean cuts and minimizing waste.