Poly coated envelopes are made from a durable paper that is coated with a layer of polyethylene. This coating provides several benefits, including moisture resistance, added strength, and enhanced durability. These envelopes often have a glossy finish, making them visually appealing.

The poly coating helps protect contents from water damage and makes the envelopes suitable for mailing items that require extra protection, such as photographs or important documents. They can come in various sizes and styles, including self-sealing options, and are often used for direct mail, promotional materials, and shipping. Their sturdy construction makes them ideal for both personal and business use.