Multilayer method: the addition of the plastic movie was the first step to help make brick containers impermeable to liquids and warmth-sealable. From the sixties, an aluminum foil started to be included to the cardboard container to be sure improved defense and extend the shelf life of the packaged product https://sustainableoilpackagings.blogspot.com/2025/01/gable-top-cartons-and-their-eco.html