Types of Waterproof Fabric
Fabric. Nylon is exceptionally strong, even stronger than polyester. Nylon and polyester are both abrasion resistant and resistant to damage from most chemicals. Nylon is also resistant to oil. Both are flammable — nylon melts then burns rapidly; polyester has a higher flammability temperature, but melts and burns at the same time.
Oilcloth, also known as enameled cloth or American cloth, is close-woven cotton duck or linen cloth with a coating of boiled linseed oil to make it waterproof. Historically, pre-Mackintosh, oilcloth was one of very few flexible, waterproof materials that were widely available.
A polyester fabric, on the other hand, is not only made of polyester but is a mix of polyester and air gaps (between yarns and between fibers). And air, obviously, is not waterproof. A polyester fabric, as any other fabric,will not be waterproof because water can go through the air gaps.
PUL is a fabric with a plastic backing coated with a thin waterproof /water resistant coating. The best thing about PUL fabrics is that it is completely waterproof, very durable, breathable with a slight cross grain stretch and you can easily wear it next to the skin, because the fabric side is soft, flexible and comfortable.
TPU is Not Really a Fabric. First of all, here’s what the acronyms stand for: PUL is Polyurethane Laminate; TPU is Thermoplastic Polyurethane; So while PUL is a fabric, TPU is simply the thin, stretchy and clear film of polyurethane plastic that is bonded to poly knit to make PUL.
Waterproof means that the fabric doesn't soak up water at all. It could be completely submerged and you would still stay dry. The jacket above is not a wool jacket, but it's completely waterproof and is made out of a synthetic fabric that looks somewhat wool-like.