Package delicate materials inside the waterproof, rip-resistant Quality Park Redi-Strip® Bubble Mailers to ensure safe delivery. From documents to CD cases, most typical day-to-day mail can fit comfortably inside these envelopes. Their smooth, white construction is backed by durable paper made of DuPont™ Tyvek® material for extra support, and the self-sealing flaps are heavily gummed for a tight hold. Seam Type: Center; Flap Type: Square; Trade Size: #13 1/2; Security Tinted: No.