Lightweight envelope saves on postage. Ideal shape and design for negatives, art boards, blueprints. Won’t abrade or chemically affect contents. Perfect solution for sending or storing large items. Clean, bright white color presents a professional image. Envelope Size: 14 1/2 x 20; Envelope/Mailer Type: Large Format; Closure: Flap-Stik® Self-Adhesive; Trade Size: N/A.