When painting your window frame you might have noticed masking tape isn't always a good idea. it is better, also in connection with condensation, to paint the edge of the window. Of course that never works perfectly and with this scraper that is not necessary. you simply paint the window along with the frame, and when it is dry you scrape the window clean again with this knife. It is suitable for the standard stanley knife blades. it prints without support material (no angles less than 30 degrees). after releasing pay some attention to the corners behind the knife. These are there to run against the frame as support for the knife when scraping. They must of course be smooth otherwise you will damage fresh paint, so check your print before use. it clamps but that is how it is supposed to be, so placing the knife requires some attention. The grip on top is the support for your index finger, that is an extra certainty that the knife stays in place, you push almost directly on the knife. Have fun with it!