Editing Knitting (section)

==Structure==
===Courses and wales===
[[Image:Knit-schematic.png|thumb|left|Structure of stockinette stitch, a common weave in knitted fabric. The meandering red path defines one ''course'', the path of the yarn through the fabric. The uppermost white loops are unsecured and "active", but they secure the red loops suspended from them. In turn, the red loops secure the white loops just below them, which in turn secure the loops below them, and so on.]]
[[Image:Knitting wales slip stitch.png|thumb|Alternating wales of red and yellow knit stitches. Each stitch in a wale is suspended from the one above it.]]

Like [[weaving]], knitting is a technique for producing a [[two-dimensional]] fabric made from a one-dimensional [[yarn]] or thread. In weaving, threads are always straight, running parallel either lengthwise (warp threads) or crosswise (weft threads). By contrast, the yarn in knitted fabrics follows a meandering path (a ''course''), forming symmetric loops (also called bights) symmetrically above and below the mean path of the yarn. These meandering loops can be easily stretched in different directions giving knit fabrics much more elasticity than woven fabrics. Depending on the yarn and [[knitting pattern]], knitted garments can stretch as much as 500%. For this reason, knitting was initially developed for garments that must be elastic or stretch in response to the wearer's motions, such as socks and hosiery. For comparison, woven garments stretch mainly along one or other of a related pair of directions that lie roughly diagonally between the warp and the weft, while contracting in the other direction of the pair (stretching and contracting with the ''[[Grain (textile)#Bias|bias]]''), and are not very elastic, unless they are woven from stretchable material such as [[spandex]]. Knitted garments are often more form-fitting than woven garments, since their elasticity allows them to contour to the body's outline more closely; by contrast, curvature is introduced into most woven garments only with sewn darts, flares, gussets and gores, the seams of which lower the elasticity of the woven fabric still further. Extra curvature can be introduced into knitted garments without seams, as in the heel of a sock; the effect of darts, flares, etc. can be obtained with [[short row (knitting)|short rows]] or by [[increase (knitting)|increasing]] or [[decrease (knitting)|decreasing]] the number of stitches. Thread used in weaving is usually much finer than the yarn used in knitting, which can give the knitted fabric more bulk and less drape than a woven fabric.

If they are not secured, the loops of a knitted course will come undone when their yarn is pulled; this is known as ''ripping out'', ''unravelling'' knitting, or humorously, ''frogging'' (because the knitter will 'rip it', this sounds like a frog croaking: 'rib-bit').<ref>{{cite web|url=http://knitty.com/ISSUEwinter03/FEATwin03TT.html|title=Techniques with Theresa, Frog pond edition|access-date=6 November 2008|archive-date=14 October 2008|archive-url=https://web.archive.org/web/20081014082347/http://www.knitty.com/issuewinter03/FEATwin03TT.html|url-status=live}}</ref> To secure a stitch, at least one new loop is passed through it. Although the new stitch is itself unsecured ("active" or "live"), it secures the stitch(es) suspended from it. A sequence of stitches in which each stitch is suspended from the next is called a ''wale''.<ref name=":0">A wale, according to ''Knitting Technology: a Comprehensive Handbook and Practical Guide'', is "a predominantly vertical column of needle loops generally produced by the same needles at successive (not necessarily all) knitting cycles. A wale starts as soon as an empty needle starts to knit" (Spencer 1989:17).</ref> To secure the initial stitches of a knitted fabric, a method for [[casting on (knitting)|casting on]] is used; to secure the final stitches in a wale, one uses a method of [[binding off (knitting)|binding/casting off]]. During knitting, the active stitches are secured mechanically, either from individual hooks (in knitting machines) or from a knitting needle or frame in hand-knitting.

[[Image:Trikot.jpg|thumb|Basic pattern of warp knitting. Parallel yarns zigzag lengthwise along the fabric, each loop securing a loop of an adjacent strand from the previous row.]]

===Weft and warp knitting===
{{See also|Warp knitting}}

There are two major varieties of knitting: weft knitting and [[warp knitting]].<ref>{{cite web
 |title=Knitting Basics 
 |publisher=Alamac American Knits LLC 
 |year=2004 
 |url=http://www.alamacknits.com/knitting.htm 
 |access-date=2006-12-27 
 |url-status=dead 
 |archive-url=https://web.archive.org/web/20070227135129/http://www.alamacknits.com/knitting.htm 
 |archive-date=2007-02-27 
}}</ref> In the more common ''weft knitting'', the wales are perpendicular to the course of the yarn.  In [[warp knitting]], the wales and courses run roughly parallel.  In weft knitting, the entire fabric may be produced from a single yarn, by adding stitches to each wale in turn, moving across the fabric as in a [[raster scan]].  By contrast, in warp knitting, one yarn is required for every wale.<ref name=":1">{{Cite book |last=Kyosev |first=Yordan |url=https://www.worldcat.org/oclc/1111501128 |title=Warp Knitted Fabrics Construction |date=2020 |isbn=978-1-4987-8017-9 |location=Boca Raton, FL |oclc=1111501128}}</ref>  Since a typical piece of knitted fabric may have hundreds of wales, warp knitting is typically done by machine, whereas weft knitting is done by both hand and machine.<ref>(Spencer 1989:11–12)</ref>  Warp-knitted fabrics such as [[Basic knitted fabrics#Tricot knitting|tricot]] and milanese are resistant to runs, and are commonly used in [[lingerie]].<ref>{{Cite book |last=Paling |first=D. F. |url=https://www.worldcat.org/oclc/500343804 |title=Warp-knitting technology. |orig-date=1965 |date=1972 |publisher=Columbine Pr |isbn=0-900298-02-2 |edition=2nd |location=[Place of publication not identified] |oclc=500343804}}</ref>

[[Image:Rundstrickmaschine Zungennadeln.jpg|thumb|left|A modern [[knitting machine]] in the process of [[weft knitting]]]]

Weft-knit fabrics may also be knit with multiple yarns, usually to produce interesting color patterns.  The two most common approaches are [[intarsia (knitting)|intarsia]] and [[Fair Isle (technique)|stranded colorwork]].  In intarsia, the yarns are used in well-segregated regions, e.g., a red apple on a field of green; in that case, the yarns are kept on separate spools and only one is knitted at any time.  In the more complex stranded approach, two or more yarns alternate repeatedly within one row and all the yarns must be carried along the row, as seen in [[Fair Isle (technique)|Fair Isle sweaters]]. [[Double knitting]] can produce two separate knitted fabrics simultaneously (e.g., two socks).  However, the two fabrics are usually integrated into one, giving it great warmth and excellent drape.

[[Image:Knitting knit and purl stitches.png|thumb|left|In the knit stitch on the left, the next (red) loop passes through the previous (yellow) loop from ''below'', whereas in the purl stitch (right), the next stitch enters from above. Thus, a knit stitch on one side of the fabric appears as a purl stitch on the other, and vice versa.]]

===Knit and purl stitches===
{{See also|List of knitting stitches}}
[[Image:Knitting red courses stockinette garter.png|thumb|Two courses of red yarn illustrating two basic fabric types. The lower red course is knit into the white row below it and is itself knit on the next row; this produces 'stockinette' stitch. The upper red course is purled into the row below and then is knit, consistent with 'garter' stitch.]]
[[File:Slipped stitch mistake.jpg|thumb|A dropped stitch, or missed stitch, is a common error that creates an extra loop to be fixed.]]

In securing the previous stitch in a wale, the next stitch can pass through the previous loop from either below or above.  If the former, the stitch is denoted as a 'knit stitch' or a 'plain stitch;' if the latter, as a 'purl stitch'. The two stitches are related in that a knit stitch seen from one side of the fabric appears as a purl stitch on the other side.

The two types of stitches have a different visual effect; the knit stitches look like 'V's stacked vertically, whereas the purl stitches look like a wavy horizontal line across the fabric. Patterns and pictures can be created in knitted fabrics by using knit and purl stitches as "[[pixel]]s"; however, such pixels are usually rectangular, rather than square, depending on the [[gauge (knitting)|gauge/tension of the knitting]]. Individual stitches, or rows of stitches, may be made taller by drawing more yarn into the new loop (an [[elongated stitch (knitting)|elongated stitch]]), which is the basis for [[uneven knitting]]: a row of tall stitches may alternate with one or more rows of short stitches for an interesting visual effect. Short and tall stitches may also alternate within a row, forming a fish-like oval pattern.

In the simplest of hand-knitted fabrics, every row of stitches are all knit (or all purl); this creates a garter stitch fabric. Alternating rows of all knit stitches and all purl stitches creates a stockinette stitch/stocking stitch pattern. Vertical stripes ([[ribbing (knitting)|ribbing]]) are possible by having alternating wales of knit and purl stitches.  For example, a common choice is 2x2 ribbing, in which two wales of knit stitches are followed by two wales of purl stitches, etc. Horizontal striping ([[welting (knitting)|welting]]) is also possible, by alternating ''rows'' of knit and purl stitches. Checkerboard patterns ([[basketweave (knitting)|basketweave]]) are also possible, the smallest of which is known as ''seed/moss stitch'': the stitches alternate between knit and purl in every wale and along every row.

Fabrics in which each knitted row is followed by a purled row, such as in stockinette/stocking stitch, have a tendency to curl—top and bottom curl toward the front (or knitted side) while the sides curl toward the back (or purled side); by contrast, those in which knit and purl stitches are arranged symmetrically (such as ribbing, garter stitch or seed/moss stitch) have more texture and tend to lie flat. Wales of purl stitches have a tendency to recede, whereas those of knit stitches tend to come forward, giving the fabric more stretchability. Thus, the purl wales in ribbing tend to be invisible, since the neighboring knit wales come forward.  Conversely, rows of purl stitches tend to form an embossed ridge relative to a row of knit stitches.  This is the basis of [[shadow knitting]], in which the appearance of a knitted fabric changes when viewed from different directions.<ref>{{cite book | last = Høxbro | first = Vivian | year = 2004 | title = Shadow Knitting | publisher = Interweave Press | location = Loveland, CO | isbn = 978-1-931499-41-5}}</ref>

Typically, a new stitch is passed through a single unsecured ('active') loop, thus lengthening that wale by one stitch.  However, this need not be so; the new loop may be passed through an already secured stitch lower down on the fabric, or even between secured stitches (a [[dip stitch (knitting)|dip stitch]]).  Depending on the distance between where the loop is drawn through the fabric and where it is knitted, dip stitches can produce a subtle stippling or long lines across the surface of the fabric, e.g., the lower leaves of a flower.  The new loop may also be passed between two stitches in the 'present' row, thus [[gather (knitting)|clustering]] the intervening stitches; this approach is often used to produce a [[smocking]] effect in the fabric.  The new loop may also be passed through 'two or more' previous stitches, producing a [[decrease (knitting)|decrease]] and merging wales together.  The merged stitches need not be from the same row; for example, a [[tuck (knitting)|tuck]] can be formed by knitting stitches together from two different rows, producing a raised horizontal welt on the fabric.

Not every stitch in a row need be knitted; some may be 'missed' (unknitted and passed to the active needle) and knitted on a subsequent row. This is known as [[slip-stitch knitting]].<ref>{{cite book | last = Bartlett | first = Roxana | year = 1998 | title = Slip-Stitch Knitting: Color Pattern the Easy Way | publisher = Interweave Press | location = Loveland, CO | isbn = 978-1-883010-32-4}}</ref>  The slipped stitches are naturally longer than the knitted ones. For example, a stitch slipped for one row before knitting would be roughly twice as tall as its knitted counterparts.  This can produce interesting visual effects, although the resulting fabric is more rigid because the slipped stitch 'pulls' on its neighbours and is less deformable. [[Slip-stitch knitting#Mosaic knitting|Mosaic knitting]] is a form of slip-stitch knitting that knits alternate colored rows and uses slip stitches to form patterns; mosaic-knit fabrics tend to be stiffer than patterned fabrics produced by other methods such as [[Fair Isle (technique)|Fair-Isle knitting]].<ref>{{cite book | last = Starmore | first = Alice | year = 1988 | title = Alice Starmore's Book of Fair Isle Knitting | publisher = Taunton | isbn = 978-0-918804-97-6}}</ref>

In some cases, a stitch may be deliberately left unsecured by a new stitch, and its wale allowed to disassemble.  This is known as [[drop-stitch knitting]], and produces a vertical ladder of see-through holes in the fabric, corresponding to where the wale had been.

===Right- and left-plaited stitches===
{{See also|Plaited stitch (knitting)}}
[[Image:Knitting plaited stitches fabric.png|thumb|The stitches on the right are right-plaited, whereas the stitches on the left are left-plaited.]]

Both knit and purl stitches may be twisted: usually once if at all, but sometimes twice and (very rarely) thrice.  When seen from above, the twist can be clockwise (right yarn over left) or counterclockwise (left yarn over right); these are denoted as right- and left-plaited stitches, respectively.  Hand-knitters generally produce right-plaited stitches by knitting or purling through the back loops, i.e., passing the needle through the initial stitch in an unusual way, but wrapping the yarn as usual.  By contrast, the left-plaited stitch is generally formed by hand-knitters by wrapping the yarn in the opposite way, rather than by any change in the needle.  Although they are mirror images in form, right- and left-plaited stitches are functionally equivalent.  Both types of plaited stitches give a subtle but interesting visual texture, and tend to draw the fabric inwards, making it stiffer.  Plaited stitches are a common method for knitting jewelry from fine metal wire.

[[File:Entrelac-hat.jpg|thumb|left|Illustration of [[entrelac]].  The blue and white wales are parallel to each other, but both are perpendicular to the black and gold wales, resembling [[basket weaving]].]]

===Edges and joins between fabrics===
The initial and final edges of a knitted fabric are known as the ''[[casting on (knitting)|cast-on]]'' and ''[[binding off (knitting)|bound/cast-off]]'' edges.  The side edges are known as the ''[[selvage (knitting)|selvages]]''; the word derives from "self-edges", meaning that the stitches do not need to be secured by anything else.  Many types of selvages have been developed, with different elastic and ornamental properties.

Vertical and horizontal edges can be introduced within a knitted fabric, e.g., for button holes, by binding/casting off and re-casting on again (horizontal) or by knitting the fabrics on either side of a vertical edge separately.

Two knitted fabrics can be joined by embroidery-based [[grafting (knitting)|grafting]] methods, most commonly the Kitchener stitch.  New wales can be begun from any of the edges of a knitted fabric; this is known as [[pick up stitches (knitting)|picking up stitches]] and is the basis for [[entrelac]], in which the wales run perpendicular to one another in a checkerboard pattern.

[[Image:Knitcable.jpg|thumb|Illustration of [[cable knitting]].  The central braid is formed from 2x2 ribbing in which the background is formed of purl stitches and the cables are each two wales of knit stitches.  By changing the order in which the stitches are knit, the wales can be made to cross.]]

===Cables, increases, and lace===
{{See also |List of knitting stitches}}
Ordinarily, stitches are knitted in the same order in every row, and the wales of the fabric run parallel and vertically along the fabric.  However, this need not be so, since the order in which stitches are knitted may be permuted so that wales cross over one another, forming a cable pattern.  Cable patterns tend to draw the fabric together, making it denser and less elastic;<ref>{{cite book | last = Leapman | first = Melissa | year = 2006 | title = Cables Untangled: An Exploration of Cable Knitting | publisher = Potter Craft | isbn = 978-1-4000-9745-6}}</ref> [[Aran sweater]]s are a common form of knitted cabling.<ref>{{cite book | last = Hollingworth | first = Shelagh | year = 1983 | title = The Complete Book of Traditional Aran Knitting | publisher = St. Martin's Press | isbn = 978-0-312-15635-0}}</ref>  Arbitrarily complex braid patterns can be done in [[cable knitting]], with the proviso that the wales must move ever upwards; it is generally impossible for a wale to move up and then down the fabric.  Knitters have developed methods for giving the illusion of a circular wale, such as appear in [[Celtic knot]]s, but these are inexact approximations.  However, such circular wales are possible using Swiss darning, a form of embroidery, or by knitting a tube separately and attaching it to the knitted fabric.

[[Image:Serweta-na.drutach2.jpg|left|thumb|In [[lace knitting]], the pattern is formed by making small, stable holes in the fabric, generally with [[yarn over]]s.]]
A wale can split into two or more wales using [[increase (knitting)|increases]], most commonly involving a [[yarn over]].  Depending on how the increase is done, there is often a hole in the fabric at the point of the increase.  This is used to great effect in [[lace knitting]], which consists of making patterns and pictures using such holes, rather than with the stitches themselves.<ref>{{cite book | last = Sowerby | first = Jane | year = 2006 | title = Victorian Lace Today | publisher = XRX Books | isbn = 978-1-933064-07-9}}<br />{{cite book | last = Swansen | first = Meg | year = 2005 | title = A Gathering of Lace | edition = 2nd | publisher = Schoolhouse Press | isbn = 978-1-893762-24-4}}</ref>  The large and many holes in lacy knitting makes it extremely elastic; for example, some Shetland "wedding-ring" shawls are so fine that they may be drawn through a wedding ring.

By combining increases and decreases, it is possible to make the direction of a wale slant away from vertical, even in weft knitting.  This is the basis for [[bias knitting]], and can be used for visual effect, similar to the direction of a brush-stroke in oil painting.

===Ornamentations and additions===
Various point-like ornaments may be added to knitting for their look or to improve the wear of the fabric.  Examples include various types of [[bobble (knitting)|bobbles]], sequins and [[bead knitting|beads]].  Long loops can also be drawn out and secured, forming a "shaggy" texture to the fabric; this is known as [[loop knitting]].  Additional patterns can be made on the surface of the knitted fabric using [[embroidery]]; if the embroidery resembles knitting, it is often called Swiss darning.  Various closures for the garments, such as frogs and buttons can be added; usually buttonholes are knitted into the garment, rather than cut.

Ornamental pieces may also be knitted separately and then attached using [[applique]].  For example, differently colored leaves and petals of a flower could be knit separately and attached to form the final picture.  Separately knitted tubes can be applied to a knitted fabric to form complex [[Celtic knot]]s and other patterns that would be difficult to knit.

Unknitted yarns may be worked into knitted fabrics for warmth, as is done in [[tufting]] and "[[weaving (knitting)|weaving]]" (also known as "couching").