Tuff Pockets are virtually indestructible yet they look like standard RedRope files. They pass the toughest tests and last for years; even when loaded with large; heavy files; catalogs or notebooks. 6-1/2" high sides and bottoms are fully lined with tear-resistant Tyvek. The tops feature special rollover reinforcement at the top. Heavyweight; 7/8" front and back panels provide rigid support and have a hidden reinforcement strip at the point of greatest stress. Pockets contain 30 percent post-consumer material.