Multilayer process: the addition of a plastic film was the first step to create brick containers impermeable to liquids and heat-sealable. Within the 1960s, an aluminum foil began to be included into the cardboard container to make sure much better protection and extend the shelf lifetime of the packaged products. https://gabletopcartonforcookingoils.blogspot.com/2025/10/liquid-soap-packaging-innovative-gable.html