Glass is a delicate, transparent surface that requires regular maintenance to keep it clean. Dirt and smudges are regular problems when it comes to maintaining glass. It is important to cover glass with plastic if you are painting in the vicinity. However, even when covered, there is always a possibility that you could get paint on your glass. When this happens, take the proper steps to get the paint off without damaging the glass's surface.
Make a solution with dish soap and water. Do not over saturate the solution with dish soap, just use a squirt of soap per cup of water. This solution will create a slippery surface and help prevent scratching when removing the paint.
Apply the solution on and around the paint on the glass. This will make the paint easier to remove with the razor blade.
Press the razor blade at a 45-degree angle against the glass and close to the edge of the paint. The entire edge should be pressed against the glass before you begin to scrape the paint. Be sure that the razor's edge is both clean and sharp to prevent scratching. It might be a good idea to test the blade against an inconspicuous portion of the glass to ensure that it will not scratch the surface.
Scrape the paint from the glass slowly, starting at the edge of the paint, with even horizontal or vertical strokes. Lift the blade directly up from the glass at the end of your stroke to prevent scratching the glass.
Repeat Steps 3 and 4 until all of the paint is removed from the glass. Reapply the solution between strokes if needed.
Clean the glass with window cleaner and squeegee the glass once all of the paint has been removed. This will remove any leftover particles from the glass and keep it clean.
Be extremely careful not to scratch the glass with the razor blade. If you are working with a tinted window, the razor could permanently damage the glass surface. Tinted windows are usually only tinted on one side; ensure you are not scraping the tinted side of the window.