We recommend using a clean polishing cloth or disc when applying Zvizzer Heavy Cut plastic polish. Spread the polish evenly on the damaged area and gradually increase the polishing speed. Press down on the sheet lightly to smooth out the scratches. Once the scratches are gone, you can use Zvizzer Fine cut to get the sheet back to its original crystal-clear state. Because Zvizzer is a water-based polish, is will be easy to judge the polishing progress. Unlike oil-based polishes, a water-based polish does not fill up scratches, making them easy to see while doing the job.