OEM Quality Park Jumbo Survivor Envelopes come in a box of 25 and feature a super-strong Tyvek construction with a convenient Flap-Stik closure. These sturdy, heavyweight envelopes are ideal for storing artwork, plates, negatives, maps, and blueprints. Designed to be moisture-resistant, they won't rip, tear, or puncture, providing a more secure alternative to standard paper envelopes.