Multilayer process: the addition of a plastic movie was the first step to help make brick containers impermeable to liquids and heat-sealable. Inside the sixties, an aluminum foil began to be added for the cardboard container to be certain improved protection and lengthen the shelf life of the packaged merchandise. http://cartongabletop.car.blog/2024/10/05/revolutionizing-packaging-the-role-of-water-in-gable-top-cartons/