If you are using acrylic in your picture frames you may have run into issues with scratching and cleaning. Although acrylic has many advantages over glass, it is not as scratch resistant. Paper towels are basically ground up wood pulp and not good for cleaning acrylic any more than they are for cleaning your camera lens. Microfiber cleaning cloths are much better and I found an excellent one frame Craftics that is smooth like a chamois, the Craftics Microfiber Smooth Towel. Most cleaners of ok for cleaning acrylic but you do not want to use any ammonia based cleaners on picture frames since the ammonia can be harmful to the artwork. I tested a number of different acrylic cleaners and found Brillianize to be my favorite. It helps get rid of the static charge, is a very safe for the artwork and the acrylic, and includes a minor polish that will help prevent static and dust build up on the frame over time.