Package delicate materials inside the waterproof, rip-resistant Quality Park Redi-Strip Tyvek 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 Tyvek paper for extra support, and the self-sealing flaps are heavily gummed for a tight hold. Envelope/Mailer Type: Cushioned/Media; Envelope Size: 9 x 12; Closure: Self-Adhesive; Trade Size: #3.