Yellow Heavy Duty Tyvek Envelopes Size: 10 x 13 inches (Open End) Quantity: Sold Individually Tyvek is a registered trademark of DuPont, the established chemical company responsible for developing this durable polymer. It is composed of high-density polyethylene fibers, a synthetic material that is extremely hard to rip and tear. Tyvek is a registered trademark of DuPont, the established chemical company responsible for developing this durable polymer. It is composed of high-density polyethylene fibers, a synthetic material that is extremely hard to rip and tear.

Yellow Heavy Duty Tyvek Envelopes Size: 10 x 13 inches (Open End) Quantity: Sold Individually Tyvek is a registered trademark of DuPont, the established chemical company responsible for developing this durable polymer. It is composed of high-density polyethylene fibers, a synthetic material that is extremely hard to rip and tear. Tyvek is a registered trademark of DuPont, the established chemical company responsible for developing this durable polymer. It is composed of high-density polyethylene fibers, a synthetic material that is extremely ha