Multilayer Program: the addition of the plastic film was the initial step to produce brick containers impermeable to liquids and heat-sealable. While in the sixties, an aluminum foil began to be included on the cardboard container to make sure greater security and prolong the shelf lifetime of the packaged merchandise. https://gable-top-cartons.mystrikingly.com/blog/eco-friendly-gable-top-containers-paper-water-paks-and-liquid-soap-packaging