I removed a bathroom vanity, and the adhesive pulled away some drywall chunks from the backsplash area. I have patched it, put 3 coats of mud, and sanded between coats. I now have a smooth area about 3 inches high and 2 feet wide on a couple of walls. I need to texture these areas to match the knock-down texture of the surrounding area. I need some suggestions on how to texture a small area to match the existing knock-down?