Editing Yarn (section)

===Synthetic fibers===
{{Main|Synthetic fiber}}
Some examples of synthetic fibers that are used as yarn are [[nylon]], [[acrylic fiber]], [[rayon]],<ref>{{cite journal |title=Rayon |journal=Time Magazine |date=1925 |volume=5 |issue=26 |pages=24–25}}</ref> and [[polyester]]. Synthetic fibers are generally extruded in continuous strands of gel-state materials. These strands are drawn (stretched), annealed (hardened), and cured to obtain properties desirable for later processing.

Synthetic fibers come in three basic forms: staple, tow, and filament. Staple is cut fibers, generally sold in lengths up to 120&nbsp;mm. Tow is a continuous "rope" of fibers consisting of many filaments loosely joined side-to-side. Filament is a continuous strand consisting of anything from one filament to many. Synthetic fiber is most often [[Units of textile measurement|measured in a weight per linear measurement basis]], along with cut length. Denier and Dtex are the most common weight to length measures. Cut-length only applies to staple fiber.

Filament extrusion is sometimes referred to as "spinning," but most people equate spinning with spun yarn production.