These 4 mil Comic Book Bags are made of Archival Polyester(Mylar) an inert material of the highest clarity. 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. Mylar contains no dangerous plasticizers, slip additives, surface coatings, antioxidants, acid- hydrolysis. This bag is a semi-rigid bag and does not require the use of a backer board. But if you do use a backer board be sure to only use certified acid free boards.
