Polyethylene Coating: A thin layer of polyethylene on either side delivers toughness. The outer layer shields the look and printing, though the interior layer acts to be a sealant, making the carton totally leakproof. The initial patents for foodstuff paperboard containers day back to the start of the last century. https://gabletopcontainers.game.blog/2025/02/07/the-rise-of-gable-top-cartons-in-packaging/