Paint Thickness Gauge

A paint thickness gauge measures the clear coat in microns so you know how much you can safely polish before burning through. Pre-purchase inspections on used cars are the classic use case — uneven readings around a panel mean it's been repainted, often hiding bodywork. If you're doing serious correction with a rotary or DA polisher, a gauge keeps you from turning a swirl-removal session into a respray. Overkill for a weekend wash-and-wax routine.