What is "Uniform Material Removal" in car polishing? "UMR" means the clear coat has been leveled evenly across the paintwork. This is achieved by OVERLAPPING your passes by at least 50% to ensure no un-polished areas are left behind. If you're sloppy with your polishing movement, you'll never get an even paintwork correction. You'll see little bits of haze in the paint instead of a consistent shine. It's a lot like mowing a lawn — if you're not overlapping, you'll miss some blades of grass here