Yarn

This article is about yarn fiber. A yarn is also a type of long and involved story, such as a shaggy dog story or a campfire yarn.

Yarn

Spools of thread

Yarn is a long continuous length of interlocked fibers, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, crewel embroidery and ropemaking. Yarn is any fiber used to construct a fabric, whereas thread is any fiber used to sew two pieces of fabric together. Yarn can also be used in many ways to produce designs on fabric.

Materials

Yarn can be made from any number of natural or synthetic fibers.

Natural fibers

The most common natural fiber is cotton, which is typically spun into fine yarn for mechanical weaving or knitting into cloth. The most commonly used animal fiber is wool harvested from sheep. For hand knitting and hobby knitting, thick wool yarns are frequently used.

Other animal fibers used include alpaca, angora, mohair, llama, cashmere, and silk. More rarely, yarn may be spun from camel, yak, possum, cat, dog, wolf, rabbit, or buffalo hair, and even turkey or ostrich feathers. Natural fibers such as these have the advantage of being slightly elastic and very breathable, while trapping a great deal of air, making for a fairly warm fabric.

Other natural fibers that can be used for yarn include linen and cotton. These tend to be much less elastic, and retain less warmth than the animal-hair yarns, though they can be stronger in some cases. The finished product will also look rather different from the woolen yarns. Other plant fibers which can be spun include bamboo, hemp, corn, and soy fiber.

Synthetic fibers

A number of synthetic materials are also commonly made into yarn, chiefly acrylic. All-acrylic yarns are available, as are wool-acrylic blends in various proportions. Some other synthetics are available as well; yarn designed for use in socks frequently contains a small percentage of nylon, and numerous specialty yarns exist.

Comparison of material properties

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 moths more readily, unless special treatments such as mercerization or superwashing are performed to strengthen, fix color, or otherwise enhance the fiber's own properties.

Protein yarns (hair, silk, feathers) may also be irritating to some people, causing contact dermatitis, hives, wheezing or other reactions. Plant fibers tend to be better tolerated by people with sensitivities to the protein yarns, and allergists frequently suggest using them or synthetics instead to prevent symptoms.

When natural fibers are burned, they tend to singe and have a smell of burnt hair; synthetic yarns tend to melt. Noting how an unidentified fiber strand burns and smells can assist in determining if it is natural or synthetic.

Synthetic yarns, because of their construction as long, extruded strands, do not pill the way natural yarns can.

Yarns combining synthetic and natural materials 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.

Construction

A Spinning Jenny, spinning machine which initiated the Industrial Revolution

Cotton being spun

Yarn is manufactured by either a spinning or air texturizing (commonly referred to as taslanizing) process. Yarn manufacturing was one of the very first processes that was industrialized.

Yarn used for fabric manufacture is made by spinning short lengths of various types of fibers. Synthetic fibers which have high strength, artificial lustre, and fire retardant qualities are blended with natural fibers which have good water absorbance and skin comforting qualities, in different proportions to manufacture yarn for fabric. The most widely used blends are cotton-polyester and wool-acrylic fiber blends.

Yarns are made up of any number of plies, each ply being a single spun yarn. These single plys of yarn are twisted in the opposite direction (plied) together to make a thicker yarn.

In some cases, thread may be monofilament, or made of a single fiber. Silk is the only natural monofilament.

Novelty yarns

A relatively recent trend is the novelty yarn. Typically these involve at least one or two strands of regular yarn twisted together with something else to make an interesting texture, and are frequently made from nylon. The major categories of novelty yarn are listed below:

• Boucle, textured or flammé yarns involve at least one or two strands of regular yarn twisted together with something else to make an interesting texture. To make boucle, the tension on one strand, as it is being spun, must be different from the other. The extra element can be a metallic thread, or a much-thicker or much-narrower strand of yarn, or yarn that varies between thick and thin. Some companies have come to put twin yarns on the market to show off combinations of one regular yarn and a novelty yarns in assorted colors or even two different types of novelty yarns.

• Eyelash yarns will be hairy and have the general aspect of faux fur once knitted up in a garment. The texture and composition of such yarns have been explored by many companies, and there are innumerable types of eyelash yarns. The most prominent types would probably be 100% polyester with a straight and relatively short hair. The hair can be curly. The core and hair of the thread can be metallic, and the hairs can sometimes be two different lengths. Some of the drawbacks of eyelash yarns is that they tend to have poor stitch definition, and that they are not flattering to curvy figures as they add bulk to a garment, so they are mostly used for accessories such as scarves.

• Ribbon yarn are not made up of the kind of ribbons used in sewing and millinery, but, rather, are ribbons made especially for knitting, usually in a tubular form. The ribbons in ribbon yarns must have elasticity to facilitate knitting.

• The fibers of ladder yarn are constructed like ladders, with a horizontal stripe of material suspended between two thinner threads.

Very often, novelty yarns will involve a lot of color change. Most often these will be obtained through the print process, in which a fiber will have different colors through a dyeing process. Sometimes the color will come through the sequence in which different colors are spun together. In some yarns the same process is used, but at the same time the color repeats are long enough to enable a self-striping feature. If the proper number of stitches is cast, then stripes will appear as the yarn is knitted into a garment. Sock yarn companies have evidently taken a great interest in self striping yarn. Such yarns have a wide array of different effects that can be obtained by knitting the yarn in the round over the number of stitches normally cast for a sock.

Some novelty yarns are even more extravagant and can be hard to describe. Katia's Rumba Mix is a ribbon that has changes in fiber within the same length involving changes of texture and changes of color. Louisa Harding's Sari Ribbon is a very wide multicolored synthetic ribbon with a streak of glittering fiber woven in its middle. Filati Bertagna's Aymara is a very fine alpaca-wool blend that is knitted in the round over a couple of stitches to make up a bigger thread.

Measurement

Yarn quantities are usually measured by weight in ounces or grams. In the United States, balls of yarn for handcrafts are usually sold in three-ounce, four-ounce, six-ounce, and eight-ounce skeins. In Europe, yarn is often sold in increments of 25 grams, with 25 g, 50 g, and 100 g being common quantities. These measurements are taken at a standard temperature and humidity, because yarn can absorb moisture from the air. The actual length of the yarn contained in a ball or skein can vary due to the inherent heaviness of the fiber and the thickness of the strand; for instance, a 50 g skein of lace weight mohair may contain several hundred meters, while a 50 g skein of bulky wool may contain only 60 meters.

There are several thicknesses of yarn, also referred to as weight. An effort by the Craft Yarn Council of America is being made to promote a standardized industry system for measuring this, numbering the weights from 1 (finest) to 6 (heaviest). Some of the names for the various weights of yarn from finest to thickest are called lace, fingering, sock, sport, double-knit (or DK), worsted, aran, bulky, and super-bulky. This naming convention is more descriptive than precise; fiber artists disagree about where on the continuum each lies, and the precise relationships between the sizes.

A more precise measurement of yarn weight, often used by weavers, is wraps per inch (wpi). The yarn is wrapped snugly around a ruler and the number of wraps that fit in an inch are counted.

Labels on yarn for handcrafts often include information on gauge, known in the UK as tension, which is a measurement of how many stitches and rows are produced per inch or per centimeter on a specified size of knitting needle or crochet hook. The proposed standardization uses a four-by-four inch/ten-by-ten centimeter knitted or crocheted square, with the resultant number of stitches across and rows high made by the suggested tools on the label to determine the gauge.

In Europe textile engineers often use the unit tex, which is the weight in grams of a kilometer of yarn, or decitex, which is a finer measurement corresponding to the weight in grams of 10 kilometers of yarn. Many other units have been used over time by different industries.

Color

Yarn drying after being dyed in the early American tradition, at Conner Prairie living history museum.

Yarn may be used undyed, or may be colored with natural or artificial dyes. Most yarns have a single uniform hue, but there is also a wide selection of variegated yarns:

• heathered or tweed: yarn with flecks of different colored fiber
• ombre: variegated yarn with light and dark shades of a single hue
• colorway: variegated yarn with two or more distinct hues (a "parrot colorway" might have green, yellow and red)
• self-striping: yarn dyed with lengths of color that will automatically create stripes in a knitted or crocheted object
• marled: yarn made from strands of different-colored yarn twisted together, sometimes in closely-related hues

See also

• Textile manufacturing

External links

• Craft Yarn Council of America
• How to buy enough yarn: Wraps per inch method
• Yarndex Information on numerous brands of yarns.