On this Fiber one 70 calorie brownies the language links are at the top of the page across from the article title. For fiber in the diet, see Dietary fiber.

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Fibers are often used in the manufacture of other materials. Synthetic fibers can often be produced very cheaply and in large amounts compared to natural fibers, but for clothing natural fibers can give some benefits, such as comfort, over their synthetic counterparts. Natural fibers develop or occur in the fiber shape, and include those produced by plants, animals, and geological processes.

Wood fiber, distinguished from vegetable fiber, is from tree sources. Animal fibers consist largely of particular proteins. Mineral fibers include the asbestos group. Asbestos is the only naturally occurring long mineral fiber. Biological fibers, also known as fibrous proteins or protein filaments, consist largely of biologically relevant and biologically very important proteins, in which mutations or other genetic defects can lead to severe diseases. Artificial or chemical fibers are fibers whose chemical composition, structure, and properties are significantly modified during the manufacturing process. In fashion, a fiber is a long and thin strand or thread of material that can be knit or woven into a fabric.

Cellulose fibers are a subset of artificial fibers, regenerated from natural cellulose. The cellulose comes from various sources: rayon from tree wood fiber, bamboo fiber from bamboo, seacell from seaweed, etc. Historically, cellulose diacetate and -triacetate were classified under the term rayon, but are now considered distinct materials. Synthetic come entirely from synthetic materials such as petrochemicals, unlike those artificial fibers derived from such natural substances as cellulose or protein. Metallic fibers can be drawn from ductile metals such as copper, gold or silver and extruded or deposited from more brittle ones, such as nickel, aluminum or iron.

Carbon fibers are often based on oxidized and via pyrolysis carbonized polymers like PAN, but the end product is almost pure carbon. Mineral fibers can be particularly strong because they are formed with a low number of surface defects, asbestos is a common one. PAN fibers are used to make carbon fiber by roasting them in a low oxygen environment. Traditional acrylic fiber is used more often as a synthetic replacement for wool.