These expandable peel and seal envelopes from JAM Paper offer the protection of DuPont™'s heavy duty Tyvek polymer. Get the protection your business and personal items deserve with these premium envelopes that are the best way to send large amounts of sensitive documents and precious items. The straight flap protects the contents inside as the peel and seal closure offers a quick and easy way to secure them. They have a semi-smooth textured finish and offer unmatched tear and water-resistant quality convenience. Tyvek is a registered trademark of DuPont, an established chemical company that develops the powerful polymer used to make these envelopes. Details: White Available in multiple sizes Straight flap with peel and seal closure Expandable with open end Tear and water-resistant 10% recycled materials 100 envelopes Tyvek polymer