Polyethylene Coating: A thin layer of polyethylene on either side gives sturdiness. The outer layer protects the design and printing, while the inner layer acts like a sealant, making the carton wholly leakproof. The 1st patents for food stuff paperboard containers day again to the start of the last century. https://gabletoppackaging.tech.blog/2025/02/25/water-in-carton-gable-top-paks-sustainable-revolution-unveiled/