Yarn

• 1. Introduction

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  Yarn is a long continuous length of interlocked fibres, and it has been reshaping human civilization since the Stone Age. Long before writing, long before the wheel became common knowledge, people were already twisting plant and animal fibres into thread. That single act of twisting changed what people could wear, what they could trade, and how they could survive. What is yarn actually made of, and how did something so humble become the foundation of global textile economies? How do modern manufacturers transform gel-state chemicals into threads that behave like nothing found in nature? And why, in an age of industrial production, do millions of people still choose to work with yarn by hand?

• 2. Ancient Roots

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  Silk production is thought to have begun in China, and thread and cloth manufacture was already well-established by the Shang dynasty, which ran from 1600 to 1050 BCE. Linen, drawn from the flax plant, carries a similarly long history. Cotton, the most common plant fibre in the world today, was being spun into fine yarns long before modern industrial methods existed. Textile trade contributed immensely to the ancient global economy, making yarn not merely a domestic craft but a driver of commerce across continents. The very mechanics of spinning, the process of twisting fibres together, can be traced to the Upper Paleolithic. Yarn spinning was also one of the first processes ever to be industrialized, signalling its importance at the dawn of the modern economy. The word "yarn" itself carries evidence of this age. It descends from the Old English gearn, related to Old High German garn, Dutch garen, Ancient Greek chorde meaning "string", and the Sanskrit hira, meaning "band". Its oldest root sense referred not to thread at all, but to entrails.

• 3. What Yarn Is Made From

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  Sheep provide the most common spun animal fibre, wool, and over generations sheep have been selectively bred to grow longer fibres because longer fibres make better yarn. That selective breeding also increases the need for shearing, since longer fleece left on the animal invites pests and causes overheating. Beyond wool, spinners have worked with alpaca, angora, mohair, llama, cashmere, and silk. Rarer still, yarn has been spun from camel, yak, possum, musk ox, vicuna, cat, dog, wolf, rabbit, bison, and chinchilla hair, as well as turkey and ostrich feathers. On the plant side, cotton dominates, but bamboo, hemp, maize, nettle, and soy fibre can all be spun as well. Synthetic options, including nylon, acrylic fibre, rayon, and polyester, are manufactured through a fundamentally different process: the raw material begins as a gel-state substance, extruded into continuous strands that are then drawn, annealed, and cured to achieve the properties the manufacturer wants. Synthetic fibres come in three basic forms. Staple is cut fibre sold generally in lengths up to 120 mm. Tow is a continuous rope of loosely joined filaments. Filament is a continuous strand of anywhere from a single thread to many. The weight-to-length measurement units most often used for synthetics are denier and dtex. T-shirt yarn offers a different angle entirely: it is made from the leftover fabric of clothing manufacture and is considered a recycled, eco-friendly product that can also be produced at home from used clothing.

• 4. Structure and Twist

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  Spun yarn is made by twisting staple fibres together into what is called a single. Multiple singles can then be twisted together in the opposite direction to create a thicker, stronger yarn. Depending on the direction of that final twist, the result is either s-twist, where the threads appear to run upward to the left, or z-twist, where they run to the right. The choice of twist direction is not cosmetic. Using both directions together in the same knitted fabric can cancel out skewing in the finished piece. The mechanical integrity of the whole structure comes from frictional contact between fibres, and the science behind that was first studied by Galileo. Beyond the basic spun yarn, manufacturers produce several distinct types. Combed yarn goes through an extra step that aligns fibres and removes shorter ones, producing a smoother, more expensive result suitable for superior-quality fabrics. Hosiery yarn is made softer with fewer twists per inch than woven counterparts, processed through melt spinning and used with circular knitting machines. Open-end yarn is spun directly from sliver fed into a rotor, with no roving frame stage, making it suitable for shorter fibres but limiting it to coarser counts. Novelty or complex yarns introduce deliberate irregularities: slub yarns alternate thick and thin sections, and metallic or synthetic fibres can be injected during spinning to create fancy effects. Filament yarn, by contrast, groups or twists very long continuous fibres together. Silk is the only natural filament; synthetic filament yarns mimic its qualities. Texturized yarn is made by air texturizing multiple filament yarns together, a process sometimes called taslanizing, and was originally developed to reduce transparency and slipperiness in synthetic fabrics while increasing warmth and absorbency.

• 5. Natural Versus Synthetic

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  Natural fibres generally demand more careful handling than synthetics. They can shrink, felt, stain, shed, fade, stretch, wrinkle, or be eaten by moths, unless treated through processes like mercerization or super washing. Protein yarns including hair, silk, and feathers can cause contact dermatitis, hives, or wheezing in some people. Those reactions are likely linked to the physical thickness and coarseness of the fibre diameter and fibre ends, not to a true allergen. Contrary to popular belief, wool allergies are practically unknown. A study published in Acta Dermato-Venereologica found that contemporary superfine and ultrafine Merino wool, with its reduced fibre diameter, does not provoke itch, is well tolerated, and in fact benefits eczema management. An unscientific but practical way to identify an unknown fibre is to burn a small strand: natural hair-type fibres singe and smell of burnt hair because, like human hair, they are protein-derived. Cotton and viscose yarns burn as a wick. Synthetics generally melt, though some are inherently flame-retardant. Pilling affects both natural and synthetic yarns. It depends on fibre content, spinning method, twist, staple length, and fabric construction. Single-ply yarns and fibres like Merino wool are especially prone to pilling, because the single-ply structure cannot hold all fibres firmly under abrasion, and Merino's short staple length allows fibre ends to escape the twist. Blended yarns inherit properties from each parent fibre in proportion to their composition. Synthetics are commonly added to lower cost, increase durability, add unusual visual effects, provide machine washability, resist stains, reduce heat retention, or lighten garment weight.

• 6. Colour and Dyeing

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  Package dyeing is the most commonly used method of adding colour. Yarn already spun in bulk is lowered into a chamber filled with dye, allowed to absorb it, then removed and dried. Skein dyeing takes a looser approach: yarn is laid in hanks or skeins over a bar and submerged in a dyebath. Space dyeing achieves multi-coloured effects by dipping sections of yarn into different colours one at a time, with a chemical called mordant applied between each step to fix the colour and prevent bleeding into the next. Warp beam dyeing is essentially a larger version of package dyeing, but it is reserved exclusively for the manufacture of woven fabrics. The visual variety that results from these techniques is wide. Heathered or tweed yarn carries flecks of different coloured fibre. Ombre yarn moves through light and dark shades of a single hue. A parrot colourway is one example of multicoloured yarn, mixing green, yellow, and red. Self-striping yarn is dyed in repeating colour lengths calculated to create automatic stripes in a knitted or crocheted object. Marled yarn is made from strands of two differently coloured yarns twisted together.

• 7. Weight, Measure, and Form

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  Yarn for handcrafts is sold by weight in ounces or grams. Common skein sizes are 25g, 50g, and 100g, with some companies using three-ounce, four-ounce, six-ounce, and eight-ounce measures instead. Because fibre absorbs moisture from the air, all textile measurements are taken at a standard temperature and humidity to keep readings consistent. A 50g skein of lace weight mohair may contain several hundred metres of yarn, while a 50g skein of bulky wool may contain only 60 metres. The Craft Yarn Council of America has promoted a standardized system that rates yarn weight on a scale from 0 to 7. Size 0 is Lace; size 1 is Super Fine; size 2 is Fine; size 3 is Light; size 4 is Medium; size 5 is Bulky; size 6 is Super Bulky; size 7 is Jumbo. Outside the United States, textile engineers more often use tex, defined as the weight in grams of 1,000 metres of yarn, or decitex, which measures the weight in grams of 10,000 metres. Yarn is wound and sold in several distinct forms. A hank is a looped bundle tied in two places to prevent tangling, preferred by many sellers because it displays the fibre's qualities well; it is often wound using a swift, a standing contraption that spins on a central axis to facilitate winding. A skein, technically yarn wound into an oblong shape, is one of the most common forms in the craft sector. Skeins come in two types: the more rectangular pull skein and the rounder bullet skein. Major retailers such as Lion Brand, and parent companies such as Yarnspirations, sell yarn in skeins. The bullet skein's inner yarn end, called a center pull, can be difficult to find and when yanked out often produces a tangle that crafters call "yarn barf".