Knitting is one of several ways to turn thread or yarn into cloth (cf weaving, crochet). Unlike woven fabric, knitted fabric consists entirely of horizontal parallel courses of yarn. The courses are joined to each other by interlocking loops in which a short loop of one course of yarn is wrapped over the bight of another course. Knitting can be done either by hand, described below, or by machine. In practice, hand knitting is usually begun (or "cast on") by forming a base series of twisted loops of yarn on a knitting needle. A second knitting needle is then used to reach through each loop (or stitch) in succession in order to snag a bight of yarn and pull a length back through the loop. This forms a new stitch. Work can proceed in the round (circular knitting) or by going back and forth in rows. Knitting can also be done by machines, which use a different mechanical system to produce nearly identical results.
Originally a male-only occupation, the first knitting trade guild was started in Paris in 1527. Knitting became a household occupation with the growing popularity of knitted stockings and by the end of the 1600s, one to two million pairs of stockings were exported from Britain to other parts of Europe.
The two basic stitches are knit (or "plain") and purl (or "wrong"). These two nominal stitches are actually identical, however, being the obverse and reverse of the same stitch. Typically, a knit stitch is formed by inserting the needle in the back of the loop (from a right-to-left perspective) and pulling a loop of yarn through to form a new loop, while a purl stitch is formed by inserting the needle in the front of the loop. However, when using the method of combined knitting (or combination knitting), both knit and purl stitches are formed by inserting the needle through the back of the loop.
A piece of knitting begins with the process of casting on, which involves the initial creation of the stitches on the needle. Different methods of cast on are used for different effects; one may be stretchy enough for lace, while another provides a decorative edging. Provisional cast ons are used when the knitting will continue in both directions from the cast on.
The body of a knitted piece may include plain stitches or a number of colour and textured patterns. The number of active stitches remains the same as when cast on unless stitches are added (an increase) or removed (a decrease) to shape the item.
Many patterns can be made by using knit and purl stitches in various combinations. If only knits or only purls are used when working back and forth in rows, the result is called garter stitch. Alternating rows of knits and purls result in stockinette stitch, also known as stocking or jersey stitch, the stitch most often used in commercial garments such as T-shirts. Different combinations of stitches can be used to form ribbing, cables, or other textures. Complex patterns can be formed by knitting with multiple colours in either intarsia or Fair Isle techniques.
Once the knitted piece is finished, the remaining live stitches are cast off. Casting (or binding) off loops the stitches across each other so they can be removed from the needle without unravelling the item. Although the mechanics are different from casting on, there are a similar variety of methods and choices to be made.
Knitted garments are most commonly made in pieces, where individual sections of the garment are knit separately and then sewn together once all the pieces have been completed. Seamless knitting, where a whole garment is knit as a single piece is also possible. Smaller items, such as socks and hats are usually knit in one piece on double pointed needles.
There are many regional styles of knitted garments with long histories, such as guernsey sweaters , jerseys, aran sweaters, and Fair Isle patterning. These are discussed in the history of knitting.
- Zimmermann, Elizabeth. (1972). Knitting Without Tears. Simon and Schuster, New York. (Reprint Edition ISBN 0-68-413505-1)
- Thomas, Mary. (1938). Mary Thomas's Knitting Book. Dover Publications. New York. (1972 Reprint Edition ISBN 0-486-22817-7)
- Rutt, Richard (2003). A history of handknitting. Interweave Press, Loveland, CO. (Reprint Edition ISBN 1-931-49937-3)
- Hiatt, June Hemmons. (1988). The principles of knitting: Methods and techniques of hand knitting. Simon and Schuster, New York.