Catalog envelopes are made with DuPont Tyvek so they are strong and moisture-resistant. Release strip makes document easily accessible to recipient, yet maintains security for your contents. Convenient peel-to-seal closure requires no moisture to close. Printed “First Class” border gives mail greater attention. 9.5″ x 12.5″ – Peel and Seal – Tyvek – 100 / Box – White