Multilayer Process: the addition of the plastic film was the initial step to produce brick containers impermeable to liquids and heat-sealable. While in the 1960s, an aluminum foil started to be additional to the cardboard container to make certain superior defense and increase the shelf lifetime of the packaged merchandise. https://gabletopcartons.health.blog/2024/10/05/embracing-innovation-water-in-gable-top-packaging/