Mono Cartons can be made from many materials: paperboard, duplex, white kraft, recycled and many more various plastics, or a composite.
Some are "food grade" for direct contact with foods. Many cartons are made out of a single piece of paperboard.
Depending on the need, this paperboard can be waxed or coated with polyethylene to form a moisture barrier. This may serve to contain a liquid product or keep a powder dry.