Compared to plastic zippers, nylon zippers have thinner teeth and appear semi transparent. It feels like plastic threads are looped out one by one.

Plastic zipper - it is a resin zipper with thick and opaque teeth. It feels like a plastic block. Usually square teeth. Nylon zippers are relatively soft, while resin zippers are relatively stiff.

Nylon zippers are commonly used for thin fabrics such as underwear, skirts, and sweaters.

Coat with resin zipper. Jeans, leather with metal zippers.