The BCW Current Comic Backer Boards are made from 24 point solid bleached sulfate, coated and buffered on one side with 3% calcium carbonate, and are precision cut to size. They are certified acid free and independent lab tested. Use these backer boards along with current comic bags (poly or mylar) to protect and store your collectible comics. Sold in bulk cases of 1000 loose boards (not wrapped in packs).