100 Pack - Current Comic Book Backing Boards100 Pack of Current Comic Book Backing Boards are essential for protecting your collection by preventing bends, creases, and damage that can reduce a comic's grade and value. Invested Alliance Comic Backing Boards are certified acid free, preventing the yellowing and deterioration that acidic materials cause over time. There's a 3% calcium carbonate coating on one side, creating an additional barrier against dust, dirt, while enhancing durability.