These backing boards along with comic bags are the most common way to protect and preserve your comic books.
They are full 24 point one side coated board, solid bleached sulfate, buffered with 3% calcium carbonate and precision cut to size. They are completely acid free and independent lab tested.
Slip your comic into the bag with a backer board behind it (shiny side toward the comic), fold the flap over and secure with a couple strips of tape.
Size 6¾" x 10½". 100 boards per pack.