Select superior Cyro brand Plexiglas — available in your choice of clear or ultraviolet filtering. For backing, you can choose from top-quality Coroplast™ or economical Foam Core brands. If you want optimal protection from a backing, Coroplast is your answer. Preferred by many museums for its archival properties, Coroplast is an acid-free, neutral-ph corrugated polypropylene board that's ideal to use as added protection behind your finest matted artwork. And, for everyday protection, economical Foam Core brand backing is your best alternative.