These 2 mil and 4 mil Comic Book Sleeves are made of Archival Polyester (Mylar) an inert material of the highest clarity. We use DuPont inert Melinex® or a suitable equivalent.
Polyester (Mylar) will not discolor, damage, or adhere to items placed inside it. It is a sturdy film that beautifully displays, timelessly protects, and gives extra support to fragile documents. Our polyester material has passed the Photo Activity Test (PAT).
We also have two styles of 4 mil polyester sleeves. They are both made of the same archival polyester material, but they have two different flap styles:
• The Open Flap style (ROF) has to be creased to form the flap and then folded over. • The Beaded Flap style (BF) has a third piece of polyester that is bead welded to the extended back of the sleeve, creating the flap.