Multilayer System: the addition of a plastic movie was the first step to create brick containers impermeable to liquids and heat-sealable. From the 1960s, an aluminum foil began to be included on the cardboard container to make certain much better safety and extend the shelf life of the packaged products. https://eco-friendlygabletopforoils.blogspot.com/2025/02/gable-top-milk-revolutionary-packaging.html