Polymailers Coffee Print 10x13 inches set of 12 pieces Easy Peel and Seal: This poly mailer features a peel away plastic strip that allows for quick and secure sealing. The adhesive strip is permanent and cannot be opened once sealed, ensuring the utmost security for your package. Lightweight and Durable: Crafted with quality and durability in mind, these poly mailers are constructed from low density polyethylene material with a thickness of 2 mil on one side. Perfect for small businesses, these bags are both lightweight and stylish, offering a wide selection of designs to spark inspiration for your mailings.