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I live in a house that is 100 plus years old. We are repainting all the rooms slowly but surely and the problem that I am running into is that because of all the settling, the trim is not straight so it is very difficult to get good clean edges when you do the trim or try to paint different colors above and below the chair rails. Any tricks or tools that you can suggest so that the lines between the walls and the woodwork will be cleaner and straighter?? Painters tape isn't working too well for me. Thanks, Teddi