What is PUL?

Polyurethane laminate (PUL) is generally a polyester interlock knit fabric that has been laminated to a thin film of polyurethane. This laminated fabric is useful as a wind and/or water barrier in the construction of fluid-splash protecting garments, shower curtains, outerwear clothing, cloth nappies / diapers and cloth menstrual pads. It is very thin and breathable. It can be machine-washed and dried.

Polyurethane laminate was first developed for hospital equipment, where reusable waterproof fabrics were needed.

Source: Wikipedia