O'Sullivan Regalite press polished sheet. The smoot, highly polished surfaces of flexible plastic windows are sensitive and can be easily scratched and marred if they are mishandles during unpacking, handling or cleaning. Plastic windows should be cleaned regularly. Be sure to hose or blow off loose dirt particles from surface and then use either plain water or mild soap and water solution. Apply with a soft cloth or tissue to gently clean window. Never use harsh brushes or abrasives when cleaning plastic windows.