Peel and Seal: With a special tape that reveals any tampering. Used for sending money or confidential documents.
Windowed: They feature a transparent plastic "window" that allows the recipient's address to be visible from the enclosed document. Suitable for bulk mailing of notifications.
Padded: They have an internal lining with air bubbles for the protection of fragile items.
Greeting Card/Invitation: Made from high-quality paper in various colors. Intended for invitations (wedding, baptism) and formal cards.
Kraft Paper: Made from durable, usually brown, Kraft paper. Suitable for heavier or bulkier contents.
