Editing Yarn (section)

== Materials ==
Yarn can be made from a number of [[natural fiber|natural]] or [[synthetic fiber]]s, or a blend of natural and synthetic fibers.

=== Natural fibers ===
{{main|Natural fiber}}

====Cotton====  
[[File:Flügelspinnmaschine.jpeg|thumb|right|[[Cotton-spinning machinery|Flyer spinning]] of cotton]]
The most common plant fiber is [[cotton]], which is typically spun into fine yarn for mechanical weaving or knitting into [[cloth]].<ref name="advameg">{{cite web
 |title       = How yarn is made
 |publisher   = Advameg
 |url         = http://www.madehow.com/Volume-3/Yarn.html
 |access-date  = 2007-06-21
 |url-status     = live
 |archive-url  = https://web.archive.org/web/20070616053622/http://www.madehow.com/Volume-3/Yarn.html
 |archive-date = 2007-06-16
}}</ref>

====Silk====
[[Silk]] is a natural [[protein]] [[fiber]], some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of [[fibroin]] and is produced by the larvae of the moth ''[[Bombyx mori]]''. Silk production is thought to have begun in China and silk thread and cloth manufacture was well-established by the [[Shang dynasty]] (1600–1050 BCE).<ref name="postrel">{{cite book |last1=Postrel |first1=Virginia |title=The Fabric of Civilization: How Textiles Made the World |date=2020 |publisher=Basic Books |location=New York |isbn=9781541617629 |page=58}}</ref>

====Linen====
[[Linen]] is another natural fiber with a long history of use for yarn and textiles. Linen fibers are derived from the [[flax]] plant. <ref>{{Cite book|url=https://books.google.com/books?id=XR4mCgAAQBAJ&q=%22linen%22+used+to+make+yarn&pg=PA70|title=J.J. Pizzuto's Fabric Science: Studio Access Card|last1=Johnson|first1=Ingrid|last2=Cohen|first2=Allen C.|last3=Sarkar|first3=Ajoy K.|date=2015-09-24|publisher=Bloomsbury Publishing USA|isbn=9781628926583}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=llOi2BeViCwC&q=%22cotton%22+used+to+make+yarn&pg=PA311|title=Soft Surfaces: Visual Research for Artists, Architects, and Designers|last=Juracek|first=Judy A.|date=2000|publisher=W. W. Norton & Company|isbn=9780393730333}}</ref>

====Other plant fibers====
[[File:40-QWSTION-BANANATEX-WARPING-LAUSCHSICHT.jpg|thumb|[[Manila hemp]] warp yarns being prepared for weaving in a modern textile factory]]
Other plant fibers which can be spun include [[bamboo]], [[hemp]], [[maize]], [[Urtica dioica|nettle]], and [[soy]] fiber.<ref name="vikki" />

====Animal fibers====
The most common spun animal fiber is [[wool]] harvested from [[sheep]]. As long fibers make better yarn, sheep have been bred over time to produce longer fibers. This increases the need for [[Sheep shearing|shearing]] to prevent pests and overheating.<ref name="doyle">{{cite journal |last1=Doyle |first1=EK |last2=Preston |first2=JWV |last3=McGregor |first3=BA |last4=Hynd |first4=PI |title=The science behind the wool industry. The importance and value of wool production from sheep. |journal=Anim Front |date=May 17, 2021 |volume=11 |issue=2 |pages=15–23 |doi=10.1093/af/vfab005 |pmid=34026311 |pmc=8127695 }}</ref>

Other animal fibers used include [[alpaca]], [[Angora wool|angora]], [[mohair]], [[llama]], [[Cashmere wool|cashmere]], and silk.<ref name="vikki">{{cite book |last1=Haffenden |first1=Vikki |last2=Patmore |first2=Frederica |title=The Knitting Book: Over 250 Step-by-Step Techniques |date=2019 |publisher=DK Publishing |location=New York |isbn=9781465482402 |url=https://books.google.com/books?id=qbW1DwAAQBAJ |access-date=6 November 2024}}</ref> More rarely, yarn may be spun from [[camel]], [[yak]], [[common brushtail possum|possum]], [[musk ox]], [[vicuña]], [[cat]], [[Chiengora|dog]], [[wolf]], [[Angora rabbit|rabbit]], [[bison]], or [[chinchilla]] hair, as well as [[Turkey (bird)|turkey]] or [[ostrich]] feathers.

===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.

===Yarn from recycled materials===
[[T-shirt]] yarn is a recycled yarn made from the same fabric as is used in T-shirts and other clothes. It is often made from the remainder fabric of clothing manufacture, and therefore is considered a recycled and [[Environmentally friendly|eco-friendly]] product. It can also be made at home out of used clothing.{{dead|date=July 2023}}<ref name="coburn">{{cite journal |last1=Coburn |first1=Robyn |title=Crafting for a Greener World: T-shirt yarns |journal=Natural Life Magazine |date=September 1, 2010 |issue=135 |pages=10–13 |url=https://www.life.ca/naturallife/1010/crafting-for-a-greener-world-refashioning-tshirt-yarns.htmhttps://www.life.ca/naturallife/1010/crafting-for-a-greener-world-refashioning-tshirt-yarns.htm |access-date=19 December 2021 }}{{Dead link|date=July 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> The resulting yarn can be used in knitted or crocheted items.<ref>{{cite news |last1=Holli |first1=Friedland |title=Knitting with recycled t-shirts |work=Baltimore Examiner |date=April 5, 2010}}</ref>

=== Comparison of material properties ===
[[File:Restored primary level spinning machine at Quarry Bank Mill.jpg|thumb|left|190px|A fully restored Derby Doubler, winding a sliver lap ready for finisher carding at [[Quarry Bank Mill]] in the UK]]
In general, natural fibers tend to require more careful handling than synthetics because they can shrink, [[felt]], stain, shed, fade, stretch, wrinkle, or be eaten by [[moth]]s more readily, unless special treatments such as [[mercerized cotton|mercerization]] or super washing are performed to strengthen, fix color, or otherwise enhance the fiber's own properties.

Some types of protein yarns (i.e.,&nbsp;hair, silk, feathers) may feel irritating to some people, causing [[contact dermatitis]], [[hives]], or [[wheeze|wheezing]]. These reactions are likely a sensitivity to thicker and coarser fiber diameter or fiber ends.<ref>{{Cite web|last=Shakespeare|first=Margaret|date=September 30, 2015|title=20 Things You Didn't Know About...Wool|url=https://www.discovermagazine.com/planet-earth/20-things-you-didnt-know-about-wool|access-date=2021-11-25|website=Discover Magazine}}</ref> In fact, contrary to popular belief, wool allergies are practically unknown. According to a study reviewing the evidence of wool as an [[allergen]] conducted by Acta Dermato-Venereologica,<ref name=pmid28350041>{{cite journal |last1=Zallmann |first1=M |last2=Smith |first2=P |last3=Tang |first3=M |last4=Spelman |first4=L |last5=Cahill |first5=J |last6=Wortmann |first6=G |last7=Katelaris |first7=C |last8=Allen |first8=K |last9=Su |first9=J |title=Debunking the Myth of Wool Allergy: Reviewing the Evidence for Immune and Non-immune Cutaneous Reactions |journal=Acta Dermato Venereologica |date=2017 |volume=97 |issue=8 |pages=906–915 |doi=10.2340/00015555-2655 |pmid=28350041 |doi-access=free |hdl=10072/355515 |hdl-access=free }}</ref> contemporary superfine or ultrafine Merino wool with their reduced fibre diameters do not provoke itch, are well tolerated and in fact benefit [[Dermatitis|eczema]] management.<ref name=pmid28350041/> Further studies suggest that known allergens applied during textile processing are minimally present in wool garments today given current industry practices and are unlikely to lead to allergic reactions.<ref>{{Cite web|title=Are you allergic to wool?|url=https://www.woolmark.com/fibre/are-you-allergic-to-wool/|access-date=2021-11-25|website=www.woolmark.com}}</ref>

When natural hair-type fibers are burned, they tend to singe and have a smell of burnt hair; this is because many, like human hair, are protein-derived. Cotton and viscose (rayon) yarns burn as a wick. Synthetic yarns generally tend to melt, though some synthetics are inherently [[Fire-retardant fabric|flame-retardant]]. Noting how an unidentified fiber strand burns and smells can assist in determining if it is natural or synthetic, and what the fiber content is.

Both synthetic and natural yarns can [[Pill (textile)|pill]]. Pilling is a function of fiber content, spinning method, twist, contiguous staple length, and fabric construction. Single ply yarns or using fibers like merino wool are known to pill more due to the fact that in the former, the single ply is not tight enough to securely retain all the fibers under abrasion, and the merino wool's short staple length allows the ends of the fibers to pop out of the twist more easily.

Yarns combining synthetic and natural fibers inherit the properties of each parent, according to the proportional composition. Synthetics are added to lower cost, increase durability, add unusual color or visual effects, provide machine washability and stain resistance, reduce heat retention, or lighten garment weight.