Editing Loom (section)

==Shedding methods==
[[File:WEAVING WITH A PIN (cropped).jpg|thumb|upright=1.7|[[Pin weaving]], not using any shedding devices. Note ordinary white plastic hair comb (beneath a red yarn, behind the box), presumably used to beat the warp against the fell.]]
{{main|Shed (weaving)}}
It is possible to weave by manually threading the weft over and under the warp threads, but this is slow. Some tapestry techniques use manual shedding. [[Pin loom]]s and [[peg loom]]s also generally have no shedding devices. [[Pile carpet]]s generally do not use shedding for the pile, because each pile thread is individually knotted onto the warps, but there may be shedding for the weft holding the carpet together.

Usually weaving uses shedding devices. These devices pull some of the warp threads to each side, so that a shed is formed between them, and the weft is passed through the shed. There are a variety of methods for forming the shed. At least two sheds must be formed, the shed and the countershed. Two sheds is enough for [[tabby weave]]; more complex weaves, such as [[twill weave]]s, [[satin weave]]s, [[diaper weave]]s, and figured (picture-forming) weaves, require more sheds.

===Heddle-bar and shed-rod===
[[File:Lisses du métier à tisser.jpg|thumb|Heddle-rod, laid across the warp threads, and tied to every other thread with short lengths of string. Tapestry loom, France, 2018]]

Heddle-rods and shedding-sticks are not the fastest way to weave, but they are very simple to make, needing only sticks and yarn. They are often used on vertical<ref name="handson">{{cite web |last1=Najeeb |first1=Hana |title=Hands On Heritage - Navajo Loom and Backstrap Weaving |work=Medium |date=22 December 2023 |url=https://medium.com/@2020ug020/hands-on-heritage-8e158c08b77c |access-date=3 December 2024}}</ref> and backstrap looms.<ref name="Samnoble_backstrap"/> They allow the creation of elaborate supplementary-weft [[brocade]]s.<ref name="Samnoble_backstrap"/> They are also used on modern tapestry looms; the frequent changing of weft colour in tapestry makes weaving tapestry slow, so using faster, more complex shedding systems isn't worthwhile. The same is true of looms for handmade [[knotted-pile carpet]]; hand-knotting each pile thread to the warp takes far more time than weaving a couple of weft threads to hold the pile in place.

At its simplest, a heddle-bar is simply a stick placed across the warp and tied to individual warp threads. It is not tied to ''all'' of the warp threads; for a plain [[tabby weave]], it is tied to every other thread. The little loops of string used to tie the wraps to the heddle bar are called ''heddles'' or ''leashes''. When the heddle-bar is pulled perpendicular to the warp, it pulls the warp threads it is tied to out of position, creating a shed.

{|width="25%" align="right" border="1" cellpadding="5" cellspacing="5"
| align="center" style="background:#e7dac1"|{{lang|en|'''Elements of a warp-weighted loom'''}}
|-
|align="right" valign="top"|[[File:Métier vertical à pesons 2.jpg|400px]]
|-
|align="left" width=60%|A warp-weighted loom with a single heddle bar. See body text for labels.
|}

A [[warp-weighted loom]] (see diagram) typically uses a heddle-bar, or several. It has two upright ''posts'' (C); they support a horizontal ''beam'' (D), which is cylindrical so that the finished cloth can be rolled around it, allowing the loom to be used to weave a piece of cloth taller than the loom, and preserving an ergonomic working height. The warp threads (F, and A and B) hang from the beam and rest against the ''shed rod'' (E). The ''heddle-bar'' (G) is tied to some of the warp threads (A, but not B), using loops of string called ''leashes'' (H). So when the heddle rod is pulled out and placed in the forked sticks protruding from the posts (not lettered, no technical term given in citation), the ''shed'' (1) is replaced by the ''counter-shed'' (2). By passing the weft through the shed and the counter-shed, alternately, cloth is woven.<ref name="Pakenham"/>

Several heddle-bars can be used side-by-side; three or more can be used to weave [[twill weave]]s, for instance.

[[File:SantaMariadelRio145.webm|thumb|upright=2|Using a heddle bar (tied with black and white heddles) and a shedding stick (plain wood, just above the heddle-bar). '''See subtitles for a step-by-step.''' The wide, flat stick is a sword batten; it is inserted lengthwise into each shed, and used to ''clear'' the shed, get it wide open and smooth, and to batten.<ref name="Samnoble_backstrap">{{cite web |title=Backstrap Looms |url=https://samnoblemuseum.ou.edu/collections-and-research/ethnology/mayan-textiles/weaving-technology/backstrap-looms/ |website=Sam Noble Museum |date=7 November 2014 |access-date=3 December 2024}}</ref> Weaving a silk [[rebozo]] with a dyed-warp pattern on a backstrap loom, [[Taller Escuela de Rebocería]] in [[Santa María del Río, San Luis Potosí]], Mexico.]]

There are also other ways to create counter-sheds. A shed-rod is simpler and easier to set up than a heddle-bar, and can make a counter-shed. A shed-rod (shedding stick, shed roll) is simply a stick woven through the warp threads. When pulled perpendicular to the threads (or rotated to stand on edge, for wide, flat shedding rods), it creates a counter shed. The combination of a heddle-bar and a shedding-stick can create the shed and countershed needed for a plain tabby weave, as in the video.

There are also slitted heddle-rods, which are sawn partway through, with evenly-placed slits. Each warp thread goes in a slit. The odd-numbered slits are at 90 degrees to the even slits. The rod is rotated back and forth to create the shed and countershed,<ref name="slit heddle bar">{{cite web |author=Luisa |date=29 January 2018 |title=DIY WEAVING LOOM WITH HEDDLE BAR |url=https://whydontyoumakeme.com/diy-weaving-loom-with-heddle-bar/ |website=Why Don't You Make Me? |access-date=3 December 2024}}</ref>  so it is often large-diameter.<ref>{{cite web |title=HOW TO WARP A FRAME LOOM WITH A HEDDLE BAR |website=Kaliko |url=https://www.kaliko.co/blogs/articles/how-to-warp-a-frame-loom-with-a-heddle-bar |access-date=3 December 2024 |language=en}}</ref>

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===Tablet weaving===
{{main|tablet weaving}}
[[File:Tablet-weaving.svg|thumb|upright=1.2|Simple one-tablet weaving]]
[[Tablet weaving]] uses cards punched with holes. The warp threads pass through the holes, and the cards are twisted and shifted to created varied sheds. This shedding technique is used for [[narrow work]]. It is also used to finish edges, weaving decorative selvage bands instead of hemming.

===Rotating-hook heddles===
{{main|Darning loom}}
[[File:Spede+Weve+Miniature+Loom+Model+1+Instructions (cropped to illustration).jpg|thumb|alt=A tiny loom with a heddle made of rotating hooks.|Darning loom with hook heddle]]
There are heddles made of flip-flopping rotating hooks, which raise and lower the warp, creating [[shed (weaving)|sheds]]. The hooks, when vertical, have the weft threads looped around them horizontally. If the hooks are flopped over on side or another, the loop of weft twists, raising one or the other side of the loop, which creates the [[shed (weaving)|shed]] and countershed.<ref>{{cite web |title=Darning Mini Wooden Loom Machine |url=https://www.miupie.com/Darning-Mini-Wooden-Loom-Machine-p3176174.html |website=Miupie |language=en}} (commercial site, but with animation showing how it works), {{cite web |last1=Morley |first1=Jasmin |title=Darning Loom Instructions |url=https://purlandfriends.com/blogs/news/darning-loom-instructions |website=Purl and Friends |access-date=7 January 2023 |date=8 September 2022}}, {{cite web |first1=Allison |last1=[not given] |title=Darning loom |url=https://ontheneedles.com/tag/darning-loom/ |website=On the Needles |date=27 December 2021 |access-date=7 January 2023 |language=en}}, {{cite web |title=How To Use A 1940s "Speed weve" Darner [repost of original 1940s instruction manual]|url=https://ragandmagpie.co.uk/blog/how-to-use-a-1940s-speede-weve |website=Rag & Magpie |date=16 April 2014 |access-date=9 December 2022}}</ref>
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===Rigid heddles===
[[File:WARP-FACED TAPE ON A RIGID HEDDLE.jpg|thumb|upright=1|alt=A rigid heddle. Widthwise slots do not quite reach either long edge, and a row of small circular holes lies between the slots, along the lengthwise midline. Warp threads pass through both slots and round holes. It heddle is carved from a solid wood plank. The long sides have a protruding triangular area, making the heddle hexagonal; the top and bottoms points are surmounted by flat knobs. The triangular areas have simple, rough incised carving.|A rigid heddle on a backstrap [[inkle loom]], unspanned.]]

Rigid [[heddle]]s are generally used on single-shaft looms. Odd warp threads go through the slots, and even ones through the circular holes, or vice versa. The shed is formed by lifting the heddle, and the countershed by depressing it. The warp threads in the slots stay where they are, and the ones in the circular holes are pulled back and forth. A single rigid heddle can hold all the warp threads, though sometimes multiple rigid heddles are used.

Treadles may be used to drive the rigid heddle up and down.
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===Non-rigid heddles===
<gallery mode=packed>
File:QSMM Heald making 2623sc.JPG|String healds, with a small eyelet called a mail in the middle of the red section, and larger lops on either side
File:QSMM Drawing-in 2653.JPG|Very similar healds, with the wooden staves threaded through them top and bottom, and the warp threads in the process of being ''drawn in'' (that is, threaded through the eyes of the healds)
File:Solv med öga.svg|How healds can thread onto staves and the warp threads (Swedish caption shows eye, and warp thread)
File:QSMM Pemberton loom 2581c.JPG|Wire healds on wire staves. A few extra healds have not had warp threads drawn in through them.
File:Heddle4.jpg|A variety of metal healds, made from wire and straps 
</gallery>
[[File:BogolanMali32.JPG|thumb|upright=1.5|This counterbalance loom has two string heddles, connected via a pulley overhead so that they rise and fall alternately. They are operated by treadles. Each treadle is a [[button#toggle|toggle]] on a string, held in the weaver's toes. He is making a simple [[tabby-weave]] cloth, [[bogolan]].]]

Rigid heddles or (above) are called "rigid" to distinguish them from string and wire heddles. Rigid heddles are one-piece, by non-rigid ones are multi-piece. Each warp thread has its own heald (also, confusingly, called a heddle). The heald has an eyelet at each end (for the staves, also called shafts) and one in the middle, called the mail, (for the warp thread). A row of these healds is slid onto two staves, the upper and lower staves; the staves together, or the staves together with the healds, may be called a ''heald frame'', which is, confusingly, also called a shaft and a harness.<ref>{{cite book |last1=Wood |first1=Errol |title=Wool Processing |via=Woolwise |url=https://www.woolwise.com/wp-content/uploads/2017/07/WOOL-482-582-12-T-11.pdf |access-date=4 December 2024 |chapter=11. Weaving technologies and structures}}</ref> Replaceable, interchangeable healds can be smaller, allowing finer weaves.

Unlike a rigid heddle, a flexible heddle cannot push the warp thread. This means that two heald frames are needed even for a plain [[tabby weave]]. [[Twill weave]]s require three or more heald frames (depending on the type of twill), and more complex figured weaves require still more frames. 

The different heald frames must be controlled by some mechanism, and the mechanism must be able to pull them in both directions. They are mostly controlled by treadles; creating the shed with the feet leaves the hands free to ply the shuttle. However in some tabletop looms, heald frames are also controlled by levers.<ref name="tableloom">{{cite web |title=Learn to weave on the Brooklyn Four Shaft Loom |publisher=Ashford |url=https://www.ashford.co.nz/images/download_pdfs/learn_to/learn_to_weave_brooklyn_four_shaft_loom.pdf |access-date=3 December 2024}}</ref>{{better source needed|date=December 2024}}

====Treadle-controlled looms====
In treadle looms, the weaver controls the shedding with their feet, by treading on [[treadle]]s. Different treadles and combinations of treadles produce different sheds. The weaver must remember the sequence of treadling needed to produce the pattern.

The precise mechanism by which the treadles control the heddles varies. Rigid-heddle treadle looms do exist, but the heddles are usually flexible. Sometimes, the treadles are tied directly to the staves (with a Y-shaped bridle so they stay level). Alternately, they may be tied to a stick called a ''lamm'', which in turn is tied to the stave, to make the motion more controlled and regular. The lamm may pivot or slide.

[[Counterbalance loom]]s are the most common type of treadle loom globally, as they are simple and give a smooth, quiet, quick motion.<ref name="glim_types"/> The heald frames are joined together in pairs, by a cord running over heddle pulleys or a heddle roller. When one heald frame rises, the other falls. It takes a pair of treadles to control a pair of frames. Counterbalance looms are usually used with two or four frames, though some have as many as ten.<ref name="glim_types"/> 

In theory each pair of heald frames has to have an equal number to warps pulled by each frame, so the patterns that can be made on them are limited.<ref name="ask_Madelyn"/> <!--although the number of sheds can be increased by adding heddle sticks and shedding sticks as supplementary shedding devices.{{cn}}--> In practice, fairly unbalanced tie-ups just make the shed a bit smaller, and as the shed on a counterbalance loom is adjustable in size and quite large to start with (compared to other types of loom), so it is entirely possible to weave good cloth on a counterbalance loom with unbalanced heald frames,<ref name="js_diff_types">{{cite web |title=Different types of looms – Jane Stafford Textiles |url=https://janestaffordtextiles.com/knowledge-base/different-types-of-looms/ |website=janestaffordtextiles.com |access-date=3 December 2024}}</ref><ref name="glim_types"/> unless the loom is extremely shallow (that is, the length of warp being pulled on is short, less than 1 meter or 3 feet), which exacerbates the slightly uneven tension.<ref name="glim_types"/> Limited patterns are not, of course, a disadvantage when weaving plainer patterns, such as tabbies and twills.

[[Jack loom]]s (also called single-tieup-looms and  rising-shed looms<ref name="JackloomsP1"/>), have their treadles connected to jacks, levers that push or pull the heald frames up; the harnesses are weighted to fall back into place by gravity. Several frames can be connected to a single treadle. Frames can also be raised by more than one treadle. This allows treadles to control arbitrary [[combination]]s of frames, which vastly increases the number of different sheds that can be created from the same number of frames. Any number of treadles can also be engaged at once, meaning that the number of different sheds that can be selected is two [[to the power of]] the number of treadles. Eight is a large but reasonable number of treadles, giving a maximum of 2<sup>8</sup>=256 sheds (some of which will probably not have enough threads on one side to be useful).{{Cn|date=December 2024}} Having more possible sheds allows more complex patterns,<ref name="ask_Madelyn"/><ref name="JackloomsP1">{{cite web |last1=Joanne |first1=Hall |title=Jack Looms - part 1 |url=https://fiberarts.org/design/articles/jackloom1.html |website=Fiberarts.org |publisher=Fiber Arts |access-date=3 December 2024 |date=30 May 2019|archive-url=https://web.archive.org/web/20190530012643/https://fiberarts.org/design/articles/jackloom1.html |archive-date=30 May 2019 }}</ref> such as [[diaper weave]]s.{{cn|date=January 2025}}

Jack looms are easy to make and to tie up (if not quite as easy as counterbalance looms). The gravity return makes jack looms heavy to operate. The shed of a jack loom is smaller for a given length of warp being pulled aside by the heddles (loom depth). The warp threads being pulled up by the jacks are also tauter than the other warp threads (unlike a counter balance loom, where the threads are pulled an equal amount in opposite directions). Uneven tension makes weaving evenly harder. It also lowers the maximum tension at which one can practically weave.<ref name="ask_Madelyn"/><ref name="JackloomsP1"/> If the threads are rough, closely-spaced, very long or numerous, it can be hard to open the sheds on the jack loom.<ref name="JackloomsP1"/> Jack looms without castles (the superstructure above the weft) have to lift the heald frames from below, and are noiser due to the impact of wood on wood; [[elastomer]] pads can reduce the noise.<ref name="glim_types"/>

[[File:Schloss Heubach, historischer Handwebstuhl im Miedermuseum.jpg|thumb|upright=2.5|A countermarch loom, with upper staves attached to the outer ends of the jacks, above. Below the heddles, there are two rows of lamms. The inner ends of the jacks are tied, in bridled pairs, to the upper lamms, which are tied to the treadles. The lower lamms are tied to the bottom staves and to the treadles. The roles of the upper and lower lamms may be swapped.<ref name="xeniakis"/>]]

In [[countermarch loom]]s, the treadles are tied to lamms,<ref name="xeniakis">{{cite web |last1=XENAKIS |first1=DAVID |title=ABOUT TYING UP A COUNTERMARCH LOOM |url=https://www.weaversschool.com/docs/Countermarch.pdf |access-date=3 December 2024}}</ref><ref name="ask_Madelyn">{{cite web |last1=van der Hoogt |first1=Madelyn |title=Ask Madelyn: Jack Looms and Counterbalance Looms |url=https://handwovenmagazine.com/looms/ |publisher=Handwoven Magazine |access-date=3 December 2024 |language=en}}</ref> which may pivot at one end or slide up and down.<ref>{{cite web |title=Different types of looms – Jane Stafford Textiles |url=https://janestaffordtextiles.com/knowledge-base/different-types-of-looms/ |website=janestaffordtextiles.com |access-date=3 December 2024}}</ref> Half of the lamms in turn connect to jacks, which also pivot, and push or pull the staves up or down.<ref name="xeniakis"/> Some countermarches have two horizontal jacks per shaft, others a single vertical jack.<ref name="glim_types"/> Each treadle is tied to ''all'' of the heald frames, moving some of them up and the rest of them down.<ref name="glim_types">{{cite web |title=Types of Looms {{!}} Learning About Looms |url=https://www.glimakrausa.com/types-of-looms/ |website=Glimakra USA |access-date=3 December 2024 |language=en}}</ref> This allows the complex [[combination|combinatorial]] treadles of a jack loom, with the large shed and balanced, even tension of a counterbalance loom, with its quiet, light operation. Unfortunately, countermarch looms are more complex, harder to build, slower to tie up,<ref name="xeniakis"/><ref name="ask_Madelyn"/><ref name="glim_types"/> and more prone to malfunction.<ref name="xeniakis"/><ref name="treadle_diagrams">{{cite web |title=Counterbalance Loom, Jack-Type loom, Countermarch loom and NEW Jack-Type loom with back hinge treadle: TECHNICAL INFORMATIONS |url=http://www.leclerclooms.com/cont.htm |website=www.leclerclooms.com |publisher=LeClerc Looms |access-date=4 December 2024}}</ref>
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====Figure harness and the drawloom====
{{anchor|Drawloom|Figure harness}}
[[File:高機模様裂-Textile fragment with incomplete repeating pattern of loom, weaver, and drawboy MET DP11389.jpg|thumb|Drawloom, with drawboy above to control the harnesses, woven as a repeating pattern in an early-18-hundreds piece of Japanese figured silk.]]
A drawloom is for weaving figured cloth. In a drawloom, a "figure harness" is used to control each warp thread separately,{{sfn|Burnham|1980|p=48}} allowing very complex patterns. A drawloom requires two operators, the weaver, and an assistant called a "drawboy" to manage the figure harness.

The earliest confirmed drawloom fabrics come from the [[Chu (state)|State of Chu]] and date c. 400 BC.<ref name="broudy 1979 124">{{harvnb|Broudy|1979|p=124}}.</ref> Some scholars speculate an independent invention in ancient [[Syria]], since drawloom fabrics found in [[Dura-Europas]] are thought to date before 256 AD.<ref name="broudy 1979 124"/>{{sfn|Forbes|1987|pp=218, 220}} The draw loom was invented in China during the Han dynasty ([[State of Liu]]?);{{contradictory inline|reason=that was two centuries later, minimum|date=January 2023}}<ref name="auto">{{Cite book |title=Explorations in the History of Machines and Mechanisms: Proceedings of HMM2012 (History of Mechanism and Machine Science) |url=https://archive.org/details/explorationshist00moon |url-access=limited |last1= Ceccarelli |first1= Marco |last2=López-Cajún |first2=Carlos  |year=2012 |publisher=Springer |pages=[https://archive.org/details/explorationshist00moon/page/n226 219]–220 |isbn=978-9400799448}}</ref> foot-powered multi-harness looms and jacquard looms were used for silk weaving and embroidery, both of which were cottage industries with imperial workshops.<ref>{{Cite book |title=A History of Mechanical Inventions |last= Usher |first= Abbott Payson |year=2011 |publisher= Dover Publications |page=54 |isbn=978-0486255934}}</ref> The drawloom enhanced and sped up the production of silk and played a significant role in Chinese silk weaving. The loom was introduced to Persia, India, and Europe.<ref name="auto"/>

====Dobby head====
[[File:Hand loom Weaving in Hooghly District 17.jpg|thumb|upright=2|Dobby-loom control mechanism. The pegs driven into the bars (hung in a loop on the left) each lift one "treadle" in a pre-determined pattern, like lifting the teeth of a [[music box]]. Hooghly District, West Bengal, 2019]]
{{main|dobby loom}}
A dobby head is a device that replaces the drawboy, the weaver's helper who used to control the warp threads by pulling on draw threads. "Dobby" is a corruption of "draw boy". Mechanical dobbies pull on the draw threads using pegs in bars to lift a set of levers. The placement of the pegs determines which levers are lifted. The sequence of bars (they are strung together) effectively remembers the sequence for the weaver. Computer-controlled dobbies use [[solenoid]]s instead of pegs.

====Jacquard head====
{{main|Jacquard loom}}
The '''Jacquard loom''' is a mechanical loom, invented by [[Joseph Marie Jacquard]] in 1801, which simplifies the process of manufacturing figured textiles with complex patterns such as [[Brocade (fabric)|brocade]], [[damask]], and [[matelasse]].<ref>{{cite book |first=Eric |last=Hobsbawm |title=The Age of Revolution |location=London |publisher=Abacus |orig-year=1962 |date=2008 |page=45}}</ref><ref>{{cite web |url=http://www.christinalynn.com/fabric-glossary.shtml |title=Fabric Glossary |work=Christina Lynn |access-date=21 November 2008 |url-status=dead |archive-url=https://web.archive.org/web/20090105170019/http://www.christinalynn.com/fabric-glossary.shtml |archive-date=5 January 2009 }}</ref> The loom is controlled by [[punched card]]s with punched holes, each row of which corresponds to one row of the design. Multiple rows of holes are punched on each card and the many cards that compose the design of the textile are strung together in order. It is based on earlier inventions by the Frenchmen [[Basile Bouchon]] (1725), Jean Baptiste Falcon (1728), and [[Jacques Vaucanson]] (1740).{{sfn|Razy|1913|p=120}} To call it a loom is a misnomer. A Jacquard head could be attached to a power loom or a handloom, the head controlling which warp thread was raised during shedding. Multiple shuttles could be used to control the colour of the weft during picking. The Jacquard loom is the predecessor to the [[Punched card input/output|computer punched card reader]]s of the 19th and 20th centuries.<ref>{{cite news |last1=Geselowitz |first1=Michael N.|title=The Jacquard Loom: A Driver of the Industrial Revolution|url=http://theinstitute.ieee.org/tech-history/technology-history/the-jacquard-loom-a-driver-of-the-industrial-revolution|work=The Institute: The IEEE news source |date=18 July 2016 |publisher=IEEE |archive-url=https://web.archive.org/web/20180401074908/http://theinstitute.ieee.org/tech-history/technology-history/the-jacquard-loom-a-driver-of-the-industrial-revolution|archive-date=1 April 2018 |access-date=31 March 2018|url-status=dead}}</ref>

<gallery>
File:Loom.jpg|The punched-card control mechanism of a [[Jacquard loom]] in use in 2009, [[Varanasi]], [[Uttar Pradesh]], India.
File:JacquardLoomsSAFALodzPoland.jpg|Hand operated Jacquard looms in the Textile Department of the Strzemiński Academy of Fine Arts in [[Łódź]], Poland.
File:JacquardWeavingPoland.jpg| Battening on a Jacquard loom in Łódź.
File:Industry during the First World War- Leicestershire Q28124.jpg|A female worker changing jacquard cards in a lace machine in a Nottingham factory (1918).
File:Indian boy and looms.jpg|Boy next to two weaving looms with the weaving pattern on reams of paper (India).
File:PunchingJacquardCardPoland.jpg|Following the pattern, holes are punched in the appropriate places on a Jacquard card.
File:Telar manual y máquina de Jacquard 12.jpg|Manual loom with double width and Jacquard loom, Colegio del Arte Mayor de la Seda of Valencia.
File:Masson Mills WTM 13 Hattersley Jacquard 5976.JPG|The Jacquard cards control the heads on a loom.
</gallery>