Fishing nets are devices made from fibers woven in a grid-like structure. Some fishing nets are also called fish traps. Fishing nets are usually meshes formed by knotting a relatively thin thread. Early nets were woven from grasses, flaxes and other fibrous plant material. Later cotton was used. Modern nets are usually made of Polyethylene, the purpose of the materials can be reflect from sunlight, tougher than nylon and more durable.