Multilayer system: the addition of the plastic film was the initial step for making brick containers impermeable to liquids and warmth-sealable. In the sixties, an aluminum foil started to be added on the cardboard container to be sure much better protection and lengthen the shelf life of the packaged item. https://gabletop.business.blog/2025/02/07/the-rise-of-gable-cartons-in-the-packaging-industry/