Multilayer technique: the addition of a plastic film was the first step to help make brick containers impermeable to liquids and warmth-sealable. While in the sixties, an aluminum foil began to be extra to the cardboard container to ensure superior security and prolong the shelf life of the packaged products. https://gabletopcontainers.blogspot.com/2025/01/water-packaging-in-gable-top-cartons.html