Polyethylene Coating: A Skinny layer of polyethylene on each side provides longevity. The outer layer shields the look and printing, even though the interior layer acts as a sealant, making the carton entirely leakproof. The initial patents for food paperboard containers day back to the beginning of the last century. https://customgablecarton.blogspot.com/2024/10/the-future-of-eco-friendly-packaging.html