What does coated or laminated bag mean?

What does coated or laminated bag mean?

A coated or laminated bulk bag is constructed with fabric that has a thin layer (usually 1 mil) of polypropylene bonded to one side. Coated bags provide a moisture barrier from condensation or low amounts of water. Coated bags do NOT provide complete 100% waterproofing. For greater protection, consider bags equipped with liners.