Spread some glue on a small sheet of paper and allow it to dry. You'll only need to use regular school glue rather than an industrial strength adhesive. As it dries, the glue should develop a distinct upper coating. Dip a cotton swab into the drying glue and apply directly over the scratched surface, being sure to dab rather than smear it. Then, allow the glued scratches to dry for about an hour. more