Multilayer system: the addition of the plastic film was the initial step to generate brick containers impermeable to liquids and heat-sealable. While in the sixties, an aluminum foil started to be extra into the cardboard container to ensure far better safety and lengthen the shelf lifetime of the packaged merchandise. https://gabletopcartons.fashion.blog/2025/10/09/gable-top-pak-eco-friendly-gable-top-cartons-and-sustainable-packaging-solutions/