Originally made of cotton or flax, most modern webbing is made of synthetic fibers such as nylon, polypropylene or polyester. Webbing is also made from exceptionally high-strength material, such as Dyneema, and Kevlar. Webbing is both light and strong, with breaking strengths readily available in excess of 10,000 lb (44.4 kN) There are two basic constructions of webbing. Flat webbing is a solid weave, with seatbelts and most backpack straps being common examples. Tubular webbing consists of a flattened tube, and is commonly used in climbing and industrial applications.