Silver Age Comic Bags and Backer Boards - 100ct 100 Ct. Silver Bags and Backing Boards Fit silver age, modern and regular comic bags Coated on one side Buffered with 3% calcium carbonate Bags are 2 mil material thickness polypropylene - Crystal clear Protect comics while handling - Use with BCW Silver Backing Boards - Bag Exterior Dimensions: 7 1/8 x 10 1/2 1 1/2 inch flap for closure Backing Boards are Certified Acid Free - Independent Lab Tested Board Exterior Dimensions: 7 X 10 1/2