Multilayer technique: the addition of a plastic film was the first step to help make brick containers impermeable to liquids and heat-sealable. From the 1960s, an aluminum foil started to be extra into the cardboard container to make certain better defense and prolong the shelf life of the packaged products. https://gablecarton.game.blog/2024/10/05/the-future-of-beverages-water-in-gable-top-cartons/