Attention collectors! Here’s an ideal size for you to mail collectibles. The 3 SFK was originally created for larger 10” x 13” photos, but this very versatile size will also hold presentation folders, books, catalogs and magazines. It’s made from durable .036” Tan Chip paperboard, it will stand up to the rigors of the mail and protect the corners of your books from damage. It’s also environmentally friendly and 100% Recyclable.