No. 10 business window envelopes feature a removable sealing strip for a clean, quick seal without moisture. Simply peel back the strip and fold the flap closed. Pressure-sensitive gum forms a permanent bond, and the paper strip keeps the adhesive free of dust, ensuring a long shelf life. These white wove envelopes are security tinted and made of 24 lb. stock, making them a reliable choice for your mailing needs.