Great for interoffice communication, the envelopes make it easy to pass documents between individuals without damaging the pages inside. The translucent cover allows the contents to be viewed from the outside, so the envelope can easily be identified. Poly XL Reusable Envelopes with a hook and loop closure are made from acid-free polypropylene. For 8-1/2 x 11 document storage. Side loading. Assorted colors include green, orange, purple, turquoise, and yellow.