Product Description Tamper proof  secure bag is a secure and tamper evident plastic packaging option used in e-commerce shipments. There are 2 basic properties of poly mailers -  Opacity - material packed inside the polymailer is not visible from outside Tamper evident glue - the flap of the bag is provided with a release strip and tamper evident glue. Once the glue is applied and flap is pasted, the bag becomes tamper evident. To unpack the material, the only way out is to tear off the poly mailer.