Editing Flax (section)

==Uses==
[[File:Brown Flax Seeds.jpg|thumb|Brown flax seeds]]
[[File:Flax seeds.jpg|thumb|Golden flax seeds]]
[[File:Ground Golden Flax Seeds (8594315026).jpg|thumb|Golden flax seed meal]]
Flax is grown for its seeds, which can be ground into a meal or turned into [[Flaxseed oil|linseed oil]], a product used as a [[nutritional supplement]] and as an ingredient in many [[wood finishing|wood-finishing]] products. Flax is also grown as an [[ornamental plant]] in gardens. Moreover, flax fibers are used to make [[linen]]. The [[specific epithet]] in its binomial name, ''usitatissimum,'' means "most useful".<ref>{{Cite book |last=McHughen |first=A. |title=Legumes and Oilseed Crops I |year=1990 |isbn=978-3-642-74450-1 |series=Biotechnology in Agriculture and Forestry |volume=10 |pages=502–514 |chapter=Flax (Linum usitatissimum L.): In Vitro Studies |doi=10.1007/978-3-642-74448-8_24}}</ref>

Flax fibers taken from the stem of the plant are two to three times as strong as cotton fibers. Additionally, flax fibers are naturally smooth and straight. Europe and North America both depended on flax for plant-based cloth until the 19th century, when cotton overtook flax as the most common plant for making [[Rag paper|rag-based paper]]. Flax is grown on the Canadian [[prairie]]s for linseed oil, which is used as a drying oil in paints and varnishes and in products such as [[linoleum]] and [[printing ink]]s.

Linseed meal, the by-product of producing linseed oil from flax seeds, is used as [[livestock]] [[fodder]].<ref name="Feedipedia">{{Cite web
| publisher= [[Institut national de la recherche agronomique|INRA]], [[CIRAD]], Association Française de Zootechnie and [[FAO]]
|title=Linseed meal |url=https://www.feedipedia.org/node/735|access-date=2023-03-27|website= Feedipedia |year=2018
| author1= Valérie Heuzé
| author2 = Gilles Tran
| author4 = Michel Lessire
| author3 = Pierre Nozière
| author5 = François Lebas
|archive-url=https://web.archive.org/web/20170712140410/http://www.feedipedia.org/node/735 |archive-date=12 July 2017
}}</ref>

==={{anchor|Flax seeds}} Flax seeds===
Flax seeds occur in brown and yellow (golden) varieties.<ref>{{Cite news |last=Grant |first=Amanda |date=6 March 2007 |title=Superfoods |work=The Guardian |location=London |url=https://www.theguardian.com/lifeandstyle/2007/mar/06/healthandwellbeing.health1 |url-status=live |archive-url=https://web.archive.org/web/20160921210717/https://www.theguardian.com/lifeandstyle/2007/mar/06/healthandwellbeing.health1 |archive-date=21 September 2016}}</ref> Most types of these basic varieties have similar [[nutrition]]al characteristics and equal numbers of short-chain [[omega-3 fatty acid]]s. Yellow flax seeds, called solin ([[trade name]] "[[Linola]]"),<ref name="CRS">{{citation
| url = http://ncseonline.org/nle/crsreports/05jun/97-905.pdf 
| title = Agriculture: A Glossary of Terms, Programs, and Laws, 2005 Edition
| editor = Jasper Womach
| display-editors = et al
| year = 2005 
| archive-url=https://web.archive.org/web/20110810044532/http://ncseonline.org/nle/crsreports/05jun/97-905.pdf 
|archive-date=10 August 2011
| url-status = usurped
| publisher = Congressional Research Service
| place = Library of Congress
}}</ref> have a similar oil profile to brown flax seeds and both are very high in omega-3s ([[alpha-linolenic acid]] (ALA), specifically).<ref>{{Cite journal |last1=Sargi |first1=Sheisa Cyléia |last2=Silva |first2=Beatriz Costa |last3=Santos |first3=Hevelyse Munise Celestino |last4=Montanher |first4=Paula Fernandes |last5=Boeing |first5=Joana Schuelter |last6=Santos Júnior |first6=Oscar Oliveira |last7=Souza |first7=Nilson Evelázio |last8=Visentainer |first8=Jesuí Vergílio |date=26 July 2013 |title=Antioxidant capacity and chemical composition in seeds rich in omega-3: chia, flax, and perilla |journal=Food Science and Technology |volume=33 |issue=3 |pages=541–548 |doi=10.1590/S0101-20612013005000057|s2cid=41096264 |doi-access=free }}</ref>
Flax seeds produce a [[vegetable oil]] known as flax seed oil or [[linseed oil]], which is one of the oldest commercial oils. It is an [[edible oil]] obtained by [[expeller pressing]] and sometimes followed by [[solvent extraction]]. Solvent-processed flax seed oil has been used for centuries as a [[drying oil]] in painting and varnishing.<ref>{{Cite web |title=Pigments through the Ages – Renaissance and Baroque (1400–1600) |url=http://www.webexhibits.org/pigments/intro/renaissance.html |url-status=live |archive-url=https://web.archive.org/web/20120719190829/http://www.webexhibits.org/pigments/intro/renaissance.html |archive-date=19 July 2012}}</ref>

Although brown flax seed varieties may be consumed as readily as the yellow ones, and have been for thousands of years, these varieties are more commonly used in paints, fiber, and cattle feed.

====Culinary====
[[File:Linseed rolls crude.JPG|alt=Small pieces of dough being topped with flax seeds before baking in a commercial bakery|thumb|Bread rolls being topped with flax seeds before baking]]

A 100-gram portion of ground flax seed supplies about {{convert|2234|kJ|kcal|abbr=off}} of [[food energy]], 41&nbsp;g of fat, 28&nbsp;g of fiber, and 20&nbsp;g of protein.<ref>{{Cite web |title=Flax nutrition profile |url=http://www.flaxcouncil.ca/english/index.jsp?p=g3&mp=nutrition |url-status=dead |archive-url=https://web.archive.org/web/20090723062551/http://www.flaxcouncil.ca/english/index.jsp?p=g3&mp=nutrition |archive-date=23 July 2009 |access-date=8 May 2008}}</ref> Whole flax seeds are chemically stable, but ground flax seed meal, because of [[Redox|oxidation]], may go [[rancidity|rancid]] when left exposed to air at room temperature in as little as a week.<ref name="DieteticAss">{{Cite journal |last1=Alpers |first1=Linda |last2=Sawyer-Morse, Mary K. |date=August 1996 |title=Eating Quality of Banana Nut Muffins and Oatmeal Cookies Made With Ground Flaxseed |journal=Journal of the American Dietetic Association |volume=96 |issue=8 |pages=794–796 |doi=10.1016/S0002-8223(96)00219-2 |pmid=8683012}}</ref> Refrigeration and storage in sealed containers will keep ground flax seed meal for a longer period before it turns rancid. Under conditions similar to those found in commercial bakeries, trained sensory panelists could not detect differences between bread made with freshly ground flax seed and bread made with flax seed that had been [[Mill (grinding)|milled]] four months earlier and stored at room temperature.<ref name="Malcolmson">{{Cite journal |last=Malcolmson |first=L.J. |date=April 2006 |title=Storage stability of milled flaxseed |journal=Journal of the American Oil Chemists' Society |volume=77 |issue=3 |pages=235–238 |doi=10.1007/s11746-000-0038-0 |s2cid=85575934}}</ref> If packed immediately without exposure to air and light, milled flax seed is stable against excessive oxidation when stored for nine months at room temperature,<ref name="Chen">{{Cite journal |last=Chen |first=Z-Y |year=1994 |title=Oxidative stability of flaxseed lipids during baking |journal=Journal of the American Oil Chemists' Society |volume=71 |issue=6 |pages=629–632 |doi=10.1007/BF02540591 |s2cid=84981982}}</ref> and under [[warehouse]] conditions, for 20 months at ambient temperatures.{{citation needed|date=March 2021}}

Three [[polyphenol|phenolic]] [[glucoside]]s—[[secoisolariciresinol diglucoside]], [[p-coumaric acid]] glucoside, and [[ferulic acid]] glucoside—are present in commercial bread containing flax seed.<ref>{{Cite journal |last=Strandås |first=C. |year=2008 |title=Phenolic glucosides in bread containing flaxseed |journal=Food Chemistry |volume=110 |issue=4 |pages=997–999 |doi=10.1016/j.foodchem.2008.02.088 |pmid=26047292}}</ref>

=====Nutrition=====

{{nutritionalvalue | name=Flax seeds | kJ=2234| protein=18.29 g | fat=42.16 g | satfat=3.663 g | monofat=7.527 g | polyfat=28.730 g | omega3fat=22.8 g | omega6fat=5.9 g | carbs=28.88 g | fiber=27.3 g | | sugars=1.55 g | iron_mg=5.73 | calcium_mg=255 | magnesium_mg=392 | phosphorus_mg=642 | potassium_mg=813| zinc_mg=4.34 | vitC_mg=0.6 | pantothenic_mg=0.985 | vitB6_mg=0.473 | folate_ug=87 | thiamin_mg=1.644 | riboflavin_mg=0.161 | niacin_mg=3.08|water=7 g  | source_usda=1 | note=[https://fdc.nal.usda.gov/fdc-app.html#/food-details/169414/nutrients Link to USDA Database entry]}}

Flax seeds are 7% water, 18% [[protein (nutrient)|protein]], 29% [[carbohydrate]]s, and 42% [[fat]] (table). In {{convert|100|g}} as a reference amount, flax seeds provide 534 [[kilocalorie]]s and contain high levels (20% or more of the [[Daily Value]], DV) of protein, [[dietary fiber]], several [[B vitamins]], and [[dietary minerals]].<ref name=nd/><ref name=usda/> Flax seeds are especially rich in [[thiamine]], [[magnesium]], and [[phosphorus]] (DVs above 90%) (table).

As a percentage of total [[fat]], flax seeds contain 54% omega-3 fatty acids (mostly [[alpha-Linolenic acid|ALA]]), 18% [[omega-9 fatty acids]] ([[oleic acid]]), and 6% [[omega-6 fatty acids]] ([[linoleic acid]]); the seeds contain 9% [[saturated fat]], including 5% as [[palmitic acid]].<ref name="nd">{{Cite web |date=2015 |title=Nutrition facts for 100 g of flaxseeds |url=http://nutritiondata.self.com/facts/nut-and-seed-products/3163/2 |url-status=live |archive-url=https://web.archive.org/web/20101205075853/http://nutritiondata.self.com/facts/nut-and-seed-products/3163/2 |archive-date=5 December 2010 |publisher=Conde Nast for USDA National Nutrient Database, version SR-21}}</ref><ref name="usda">{{Cite web |date=2015 |title=Full Report (All Nutrients): 12220, Seeds, flaxseed per 100 g |url=http://ndb.nal.usda.gov/ndb/foods/show/3745?fg=&man=&lfacet=&count=&max=&sort=&qlookup=&offset=&format=Full&new=&measureby= |url-status=dead |archive-url=https://web.archive.org/web/20140920222846/http://ndb.nal.usda.gov/ndb/foods/show/3745?fg=&man=&lfacet=&count=&max=&sort=&qlookup=&offset=&format=Full&new=&measureby= |archive-date=20 September 2014 |publisher=USDA National Nutrient Database version SR-27}}</ref> Flax seed oil contains 53% 18:3 omega-3 fatty acids (mostly ALA) and 13% 18:2 omega-6 fatty acids.<ref name=nd/>

=====Health research=====
A [[meta-analysis]] showed that consumption of more than 30&nbsp;g of flax-seed daily for more than 12&nbsp;weeks reduced body weight, [[body mass index]] (BMI), and waist circumference for persons with a BMI greater than 27.<ref name="pmid28635182">{{Cite journal |last1=Mohammadi-Sartang |first1=M. |last2=Mazloom |first2=Z. |last3=Raeisi-Dehkordi |first3=H. |last4=Barati-Boldaji |first4=R. |last5=Bellissimo |first5=N. |last6=Totosy de Zepetnek |first6=J. O. |date=September 2017 |title=The effect of flaxseed supplementation on body weight and body composition: a systematic review and meta-analysis of 45 randomized placebo-controlled trials: Flaxseed and body composition |journal=Obesity Reviews |volume=18 |issue=9 |pages=1096–1107 |doi=10.1111/obr.12550 |pmid=28635182 |s2cid=5587045}}</ref> Another meta-analysis showed that consumption of flax seeds for more than 12&nbsp;weeks produced small reductions in [[Systole|systolic blood pressure]] and [[Diastole|diastolic blood pressure]].<ref name="pmid25740909">{{Cite journal |vauthors=Khalesi S, Irwin C, Schubert M |year=2015 |title=Flaxseed consumption may reduce blood pressure: a systematic review and meta-analysis of controlled trials |journal=[[Journal of Nutrition]] |volume=145 |issue=4 |pages=758–65 |doi=10.3945/jn.114.205302 |pmid=25740909 |doi-access=free|hdl=10072/128716 |hdl-access=free }}</ref> A third showed that consuming flax seed or its derivatives may reduce total and [[LDL-cholesterol]] in the blood, with greater benefits in women and people with high [[cholesterol]].<ref>{{Cite journal |last1=Pan |first1=A |last2=Yu |first2=D |last3=Demark-Wahnefried |first3=W |last4=Franco |first4=OH |last5=Lin |first5=X |date=August 2009 |title=Meta-analysis of the effects of flaxseed interventions on blood lipids |journal=The American Journal of Clinical Nutrition |volume=90 |issue=2 |pages=288–97 |doi=10.3945/ajcn.2009.27469 |pmc=3361740 |pmid=19515737}}</ref> A fourth showed a small reduction in [[c-reactive protein]] (a marker of inflammation) only in persons with a body mass index greater than 30.<ref name="pmid26959052">{{Cite journal |last1=Ren |first1=Guan-Yu |last2=Chen |first2=Chun-Yang |last3=Chen |first3=Guo-Chong |last4=Chen |first4=Wei-Guo |last5=Pan |first5=An |last6=Pan |first6=Chen-Wei |last7=Zhang |first7=Yong-Hong |last8=Qin |first8=Li-Qiang |last9=Chen |first9=Li-Hua |date=4 March 2016 |title=Effect of Flaxseed Intervention on Inflammatory Marker C-Reactive Protein: A Systematic Review and Meta-Analysis of Randomized Controlled Trials |journal=Nutrients |volume=8 |issue=3 |pages=136 |doi=10.3390/nu8030136 |pmc=4808865 |pmid=26959052 |doi-access=free}}</ref>

=====Linseed oil=====
{{excerpt|Linseed oil}}

=====Safety=====
Flax seed and its oil are [[generally recognized as safe]] for human consumption.<ref>{{Cite web |last=Cheeseman MA |date=24 August 2009 |title=GRAS Petition by Flax Canada, Agency Response Letter GRAS Notice No. GRN 000280 |url=https://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/Noticeinventory/ucm181935.htm |url-status=live |archive-url=https://web.archive.org/web/20150617234254/https://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/Noticeinventory/ucm181935.htm |archive-date=17 June 2015 |access-date=1 June 2015 |publisher=U.S. Food and Drug Administration}}</ref> Like many common foods, flax contains small amounts of cyanogenic [[glycoside]],<ref>{{Cite journal |last1=Cunnane |first1=SC|last2=Ganguli |first2=S|last3=Menard |first3=C|last4=Liede |first4=AC|last5=Hamadeh |first5=MJ|last6=Chen |first6=ZY|last7=Wolever |first7=TM|last8=Jenkins |first8=DJ |year=1993 |title=High alpha-linolenic acid flaxseed (''Linum usitatissimum''): some nutritional properties in humans |journal=Br J Nutr |volume=69 |issue=2 |pages=443–53 |doi=10.1079/bjn19930046 |pmid=8098222 |doi-access=free}}</ref> which is nontoxic when consumed in typical amounts.<ref name="efsa">{{cite journal | author=EFSA Panel on Contaminants in the Food Chain| title=Evaluation of the health risks related to the presence of cyanogenic glycosides in foods other than raw apricot kernels | journal=EFSA Journal|date=11 April 2019 | volume=17 | issue=4 | pages=e05662 | doi=10.2903/j.efsa.2019.5662 | pmid=32626287 | pmc=7009189 | doi-access=free }}</ref> Typical concentrations (for example, 0.48% in a sample of defatted dehusked flax seed meal) can be removed by special processing.<ref>{{Cite journal |vauthors=Singh KK, Mridula D, Rehal J, Barnwal P |year=2011 |title=Flaxseed: a potential source of food, feed and fiber |journal=Crit Rev Food Sci Nutr |volume=51 |issue=3 |pages=210–22 |doi=10.1080/10408390903537241 |pmid=21390942 |s2cid=21452408}}</ref>

====Fodder====
After crushing the seeds to extract linseed oil, the resultant linseed meal is a [[protein]]-rich [[Animal feed|feed]] for [[ruminant]]s, [[rabbit]]s, and fish.<ref name=Feedipedia/> It is also often used as feed for [[swine]] and [[poultry]], and has also been used in horse concentrate and [[dog food]].<ref name="Maddock1">{{Cite web |last1=Maddock |first1=Travis D. |last2=Anderson, Vernon L. |last3=Lardy, Greg P. |title=Using Flax in Livestock Diets |url=http://www.ag.ndsu.edu/pubs/ansci/beef/as1283w.htm |archive-url=https://web.archive.org/web/20120222030813/http://www.ag.ndsu.edu/pubs/ansci/beef/as1283w.htm |archive-date=22 February 2012 |publisher=North Dakota State University |pages=53–62}}</ref> The high omega-3 fatty acid ([[alpha-linolenic acid|ALA]]) content of linseed meal "softens" milk, eggs, and meat, which means it causes a higher [[unsaturated fat]] content and thus lowers its storage time.<ref name=Feedipedia/> The high omega-3 content also has a further disadvantage, because this fatty acid [[oxidise]]s and goes [[Rancidification|rancid]] quickly, which shortens the storage time. [[Linola]] was developed in Australia and introduced in the 1990s with less omega-3, specifically to serve as [[fodder]].<ref name="CRS" /><ref name="Dribnenkil1995">{{Cite journal |last=J. C. P. Dribnenkil and A. G. Green |year=1995 |title=Linola '947' low linolenic acid flax |journal=Canadian Journal of Plant Science |volume=75 |issue=1 |pages=201–202 |doi=10.4141/cjps95-036 |doi-access=free}}</ref> Another disadvantage of the meal and seed is that it contains a [[vitamin B6]] ([[pyridoxine]]) antagonist, and may require this vitamin be supplemented, especially in [[chicken]]s, and furthermore linseeds contain 2–7% of [[mucilage]] (fibre), which may be beneficial in humans<ref name=Feedipedia/> and cattle,<ref name=Maddock1/> but cannot be digested by non-ruminants and can be detrimental to young animals, unless possibly treated with [[enzyme]]s.<ref name=Feedipedia/>

Linseed meal is added to [[Cattle feeding|cattle feed]] as a protein [[Dietary supplement|supplement]]. It can only be added at low percentages due to the high fat content, which is unhealthy for ruminants.<ref name=Maddock1/> Compared to oilseed meal from [[Brassicaceae|crucifers]] it measures as having lower nutrient values,<ref name=Feedipedia/> however, good results are obtained in cattle, perhaps due to the mucilage, which may aid in slowing digestion and thus allowing more time to absorb nutrients.<ref name=Feedipedia/><ref name=Maddock1/> One study found that feeding flax seeds may increase omega-3 content in [[beef]], while another found no differences. It might also act as a substitute for [[tallow]] in increasing [[marbled meat|marbling]].<ref name=Maddock1/><ref name="Maddock2">{{Cite journal |last1=Maddock |first1=T. D. |last2=Bauer |first2=M. L. |last3=Koch |first3=K. B. |last4=Anderson |first4=V. L. |last5=Maddock |first5=R. J. |last6=Barceló-Coblijn |first6=G. |last7=Murphy |first7=E. J. |last8=Lardy |first8=G. P. |date=1 June 2006 |title=Effect of processing flax in beef feedlot diets on performance, carcass characteristics, and trained sensory panel ratings1 |journal=Journal of Animal Science |volume=84 |issue=6 |pages=1544–1551 |doi=10.2527/2006.8461544x |pmid=16699112}}</ref> In the US, flax-based feed for ruminants is often somewhat more expensive than other feeds on a nutrient basis.<ref name="Lardy2015">{{Cite report |url=https://www.ag.ndsu.edu/publications/livestock/alternative-feeds-for-ruminants/as1182.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.ag.ndsu.edu/publications/livestock/alternative-feeds-for-ruminants/as1182.pdf |archive-date=2022-10-09 |url-status=live |title=Alternative feeds for ruminants |last1=Lardy |first1=Greg P. |last2=Anderson |first2=Vern L. |date=October 2015 |publisher=[[North Dakota State University]] Extension Service |pages=9, 20 |docket=AS1182 (Revised) |last3=Dahlen |first3=Carl |access-date=4 October 2019}}</ref> [[Sheep]] feeding on low quality [[forage]] are able to eat a large amount of linseed meal, up to 40% in one test, with positive consequences. It has been fed as a supplement to [[water buffaloes]] in India and provided a better diet than forage alone, but not as good as when substituted with [[soybean|soy]] meal. It is considered an inferior protein supplement for swine because of its fibre, vitamin antagonist, high omega-3 content, and its low lysine content, and can only be used in small amounts in the feed. Although it may increase the omega-3 content in eggs and meat, it is also an inferior and potentially toxic feed for poultry, although it can be used in small amounts. The meal is an adequate and traditional source of protein for rabbits at 8–10%. Its use in fish feeds is limited.<ref name=Feedipedia/>

Raw, immature linseeds contain an amount of [[cyanogenic]] compounds and can be dangerous for [[monogastric]] animals, like horses and rabbits. Boiling removes the danger. This is not an issue in meal cake due to the processing temperature during oil extraction.<ref name=Feedipedia/><ref name=Lardy2015/>

Flax [[straw]] left over from the harvesting of oilseed is not very nutritious; it is tough and indigestible and is not recommended for use as ruminant fodder, although it may be used as bedding or [[baler|baled]] as [[windbreak]]s.<ref name=Lardy2015/>

==== Warfare ====
A [[United Kingdom|British]] [[Biological warfare|biowarfare]] [[military operation plan]] developed from 1942 to 1944 during [[World War II]] was planned to disseminate linseed with anthrax spores to be eaten by livestock, and eventually consumed by the human population.<ref>{{Cite web |last=Burke |first=Myles |date=22 April 2024 |title=Britain's mysterious WW2 'island of death' |url=https://www.bbc.com/culture/article/20240419-britains-mysterious-ww2-island-of-death? |access-date=17 February 2025 |website=BBC Culture}}</ref> This would have led to widespread death, but the plan was eventually abandoned for Operation Overlord.

===Flax fibers===
[[File:Heckling Shop Irvine.JPG|thumb|An 18th-century [[Heckling (flax)|heckling]] shop once used to prepare flax fibers. [[North Ayrshire]], Scotland.]]

Flax fiber is extracted from the [[Bast (biology)|bast]] beneath the surface of the stem of the flax plant. Flax fiber is soft, lustrous, and flexible; bundles of fiber have the appearance of blonde hair, hence the description "flaxen" hair. It is stronger than cotton fiber, but less elastic.

[[File:Flax field.JPG|thumb|A flax field in bloom in [[North Dakota]]]]

The use of flax fibers dates back tens of millennia;<ref name="VintageThreads" /> [[linen]], a refined textile made from flax fibers, was worn widely by [[Sumer]]ian priests more than 4,000 years ago.<ref>{{Cite book |last=Kramer |first=Samuel Noah |url=http://oi.uchicago.edu/sites/oi.uchicago.edu/files/uploads/shared/docs/sumerians.pdf |title=The Sumerians: Their history, culture and character |date=1963 |publisher=The University of Chicago Press |isbn=0-226-45237-9 |page=104 |author-link=Samuel Noah Kramer |archive-url=https://web.archive.org/web/20160327203605/http://oi.uchicago.edu/sites/oi.uchicago.edu/files/uploads/shared/docs/sumerians.pdf |archive-date=27 March 2016 |url-status=live}}</ref> Industrial-scale flax fiber processing existed in antiquity. A [[Bronze Age]] factory dedicated to flax processing was discovered in [[Euonymeia]], Greece.<ref name="Kaza2015">{{Cite book |last=Kaza-Papageorgiou |first=Konstantina |title=The Ancient Astiki Odos and the Metro beneath Vouliagmenis Avenue |date=30 November 2015 |publisher=Kapon Editions |isbn=978-9606878947 |location=Athens, Greece}}</ref>

The best grades are used for fabrics such as [[damask]]s, [[lace]], and [[Bed sheet|sheeting]]. Coarser grades are used for the manufacturing of [[twine]] and [[rope]], and historically, for [[canvas]] and [[webbing equipment]]. Flax fiber is a raw material used in the high-quality paper industry for the use of printed [[banknote]]s, laboratory paper ([[Blotting paper|blotting]] and [[Filter paper|filter]]), [[rolling paper]] for [[cigarette]]s, and [[tea bag]]s.<ref>{{Cite book |last=Chand, Navin. |title=Tribology of natural fiber polymer composites |date=2008 |publisher=Woodhead Publishing |others=Fahim, Mohammed., Institute of Materials, Minerals, and Mining. |isbn=978-1-84569-505-7 |location=Cambridge, England |oclc=425959562}}</ref>

[[Flax mill]]s for spinning flaxen [[yarn]] were invented by [[John Kendrew (inventor)|John Kendrew]] and [[Thomas Porthouse]] of [[Darlington]], [[England]], in 1787.<ref>{{Cite book |last=Wardey |first=A. J. |title=The Linen Trade: Ancient and Modern |publisher=Routledge |year=1967 |isbn=978-0-7146-1114-3 |page=752}}</ref> New methods of processing flax <!-- out of date and the rising price of cotton --> have led to renewed interest in the use of flax as an industrial fiber.

====Preparation for spinning====
[[File:Labeledstemforposter copy.jpg|thumb|Stem cross-section, showing locations of underlying tissues: Ep = [[epidermis (botany)|epidermis]]; C = [[cortex (botany)|cortex]]; BF = [[bast (biology)|bast]] fibers; P = [[phloem]]; X = [[xylem]]; Pi = [[pith]]]]
[[File:Rhof-flachsbearbeitung.ogv|thumb|Threshing, retting, and dressing flax at the [[Roscheider Hof Open Air Museum]] (Germany)]]

Before the flax fibers can be spun into linen, they must be separated from the rest of the stalk. The first step in this process is [[retting]], which is the process of rotting away the inner stalk, leaving the outer parts intact. At this point, straw, or coarse outer stem ([[cortex (botany)|cortex]] and [[epidermis (botany)|epidermis]]), is still remaining. To remove this, the flax is "broken", the straw is broken up into small, short bits, while the actual fiber is left unharmed. [[Scutching]] scrapes the outer straw from the fiber. The stems are then pulled through "hackles", which act like combs to remove the straw and some shorter fibers out of the long fiber.{{Citation needed|date=June 2021}}

=====Retting flax=====
Several methods are used for [[retting]] flax. It can be retted in a pond, stream, field, or tank. When the retting is complete, the bundles of flax feel soft and slimy, and quite a few fibers stand out from the stalks. When wrapped around a finger, the inner woody part springs away from the fibers. Pond retting is the fastest. It consists of placing the flax in a pool of water which will not evaporate. It generally takes place in a shallow pool which will warm up dramatically in the sun; the process may take from a few days to a few weeks. Pond-retted flax is traditionally considered of lower quality, possibly because the product can become dirty, and is easily over-retted, damaging the fiber. This form of retting also produces quite an odor. Stream retting is similar to pool retting, but the flax is submerged in bundles in a stream or river. This generally takes two or three weeks longer than pond retting, but the end product is less likely to be dirty, does not smell as bad, and because the water is cooler, is less likely to be over-retted. Both pond and stream retting were traditionally used less because they pollute the waters used for the process.{{Citation needed|date=June 2021}}

In field retting, the flax is laid out in a large field, and dew is allowed to collect on it. This process normally takes a month or more but is generally considered to provide the highest quality flax fibers, and it produces the least pollution.<ref>{{Cite book |last=H V Sreenivasa Murthy |title=Introduction to Textile Fibres (Woodhead Publishing India in Textiles) |publisher=Woodhead Publishing India PVT LTD (2017 Revised edition) |year=2016 |isbn=9789385059094 |location=New Delhi, India |pages=3.1.1}}</ref>

Retting can also be done in a plastic trash can or any type of water-tight container of wood, concrete, earthenware, or plastic. Metal containers will not work, as acid is produced when retting, and it would [[corrode]] the metal. If the water temperature is kept at {{convert|80|F|C|order=flip}}, the retting process under these conditions takes 4 or 5 days. If the water is colder, it takes longer. Scum collects at the top, and an odor is given off the same as in pond retting. 'Enzymatic' retting of flax has been researched as a technique to engineer fibers with specific properties.<ref>{{Cite journal |last=Akin Dodd |first=Foulk |year=2008 |title=Pectinolytic enzymes and retting |journal=BioResources |volume=3 |issue=1 |pages=155–169}}</ref><ref>{{Cite journal |last=Akin Dodd |first=Foulk |year=2001 |title=Processing techniques for improving enzyme-retting of flax |journal=Industrial Crops and Products |volume=13 |issue=3 |pages=239–248 |doi=10.1016/s0926-6690(00)00081-9}}</ref>

=====Dressing the flax=====
{{Unreferenced section|date=June 2021}}
<gallery class="center">
File:Harfleur - Compagnons duellistes - teillage du lin.jpg|Breaking flax
File:Harfleur - Compagnons duellistes - battage du lin.jpg|Scutching flax
File:Harfleur - Compagnons duellistes - peignage du lin.jpg|Heckling flax
File:Flax fibers.JPG|Flax fiber in different forms, before and after processing 
</gallery>

Dressing the flax is the process of removing the straw from the fibers. Dressing consists of three steps: breaking, scutching, and heckling. The breaking breaks up the straw. Some of the straw is scraped from the fibers in the scutching process, and finally, the fiber is pulled through heckles to remove the last bits of straw.

Breaking breaks up the straw into short segments. <!-- more how-to To do it, take the bundles of flax and untie them. Next, in small handsful, put it between the beater of the breaking machine (a set of wooden blades that mesh together when the upper jaw is lowered, which look like a paper cutter but instead of having a big knife it has a blunt arm), and beat it till the three or four inches that have been beaten appear to be soft. Move the flax a little higher and continue to beat it till all is soft, and the wood is separated from the fiber. When half of the flax is broken, hold the beaten end and beat the rest in the same way as the other end was beaten, till the wood is separated. -->

[[Scutching]] removes some of the [[straw]] from the fiber<!-- , it helps to swing a wooden scutching knife down the fibers while they hang vertically, thus scraping the edge of the knife along the fibers and pulling away pieces of the stalk. Some of the fiber will also be scutched away, this cannot be helped and is a normal part of the process -->.

[[Heckling (flax)|Heckling]] is pulling the fiber through various sizes of [[heckling comb]]s or heckles. A heckle is a bed of "nails"—sharp, long-tapered, tempered, polished steel pins driven into wooden blocks at regular spacing. <!-- A good progression is from four pins per square inch to 12, to 25 to 48 to 80. The first three will remove the straw, and the last two will split and polish the fibers. Some of the finer stuff that comes off in the last hackles is called [[tow]] and can be [[carding|carded]] like wool and [[spinning (textiles)|spun]]. It will produce a coarser yarn than the fibers pulled through the heckles because it will still have some straw in it. -->