Half Back acid free backing boards are the highest quality backing board available anywhere! Made from 100% acid-free, 24 mil thick cardboard to ensure extra rigidity and protection. Produced with a 3% alkaline buffer throughout and maintains ph of 8.0+ to further ensure the preservation of your collectible. Meets strict U.S. Government standards for archival storage. Features 100% Acid Free Backing Boards Protects Your Collectibles from the Effects of Aging Produced with a 3% Alkaline Buffer Maintains ph of 8.0+ Meets Strict U.S. Government Standards Measurements 100 Pack 6-3/4" X 10-1/2" 24 mil Thick Cardboard
