Lightweight, moisture- and rip-resistant mailers made of DuPont? Tyvek? help to reduce shipping costs. Clean, crisp look conveys a professional image. Flap-Stik? peel-and-press flap seals securely. Envelope Size: 10 x 13; Envelope/Mailer Type: Catalog; Closure: Self-Adhesive; Trade Size: #97.