Modern fishing lines intended for spinning, spin cast, or bait casting reels are almost entirely made from artificial substances, including nylon, polyvinylidene fluoride (PVDF, also called fluorocarbon), polyethylene. The most common type is monofilament, made of a single strand. Fishermen often use monofilament because of its buoyant characteristics and its ability to stretch under load. The line stretch has advantages, such as dampening the force when setting the hook and when fighting strong fish. On very far distances the dampening may become a disadvantage. Recently, other alternatives to standard nylon monofilament lines have been introduced made of copolymers or fluorocarbon, or a combination of the two materials. Anglers often utilize fluorocarbon when they need their baits to stay closer to the bottom without the use of heavy sinkers. There are also braided fishing lines, cofilament and thermally fused lines, also known as 'superlines' for their small diameter, lack of stretch, and great strength relative to standard nylon monofilament lines. Braided, thermally fused, and chemically fused varieties of 'superlines' are now readily available.