Specialty Binder Pockets are made from acid-free, archival quality polypropylene which contains an additional additive. Visit c-line/attributes to learn about the environmental attributes of this product. C-Line, a leading manufacturer of office supplies with a product line that features storage, identification and organization products, offers a range of Green office products for your storage and organizational needs. These Biodegradable Binder Pockets are made from acid-free, archival quality polypropylene which contains an additional additive that allows it to biodegrade when tested according to the ASTM D5511. The 1 Inch gusset expands for additional capacity and the Velcro closure ensures your letter size documents are safe and secure while in any standard 3-ring binder.