How Wool is Made

It wouldn’t be spinning a yarn to say that the benefits of wool are myriad. Strong and durable, soft and comfortable, this natural fibre will keep you warm in the winter and cool in the summer. It’s even hypoallergenic and resistant to mould and mildew. But how is wool made? What’s more, how is yarn made? Read on to find out.

Engineering How It’s Made
20 September 2022

From cosy winter hats and jumpers to Scottish tweed and luxurious carpets, wool is a natural fibre that keeps sheep warm in the winter and cool in the summer. But did you know wool also comes from camels, llamas, alpacas and even goats?

It’s waterproof and resistant to extremely high temperature and a by-product called lanolin – also known as wool wax – is widely used in beauty products, lip balm, lubricants, shoe polish and even as a coating for metal to prevent rust. Wool is one of the most versatile materials on Earth.

Read on to find out how wool is made as well as discovering the answers to the questions ‘how do they make wool in a factory‘ and ‘how is yarn made’

Wool - A Sheared History

Wool. It's all down to sheep! (Photo: Peter Cade via Getty Images)

Before looking into ‘how is wool produced’, it’s worth looking at its history. Humans are thought to have first domesticated sheep around 11,000 years ago. As for the oldest wool clothing ever found, this has been dated to between 4000 and 3000 BC.

By 1000 BC the British and Spanish were Europe’s primary wool producers. It was sold as a commodity at French trade fairs in the Middle Ages, from where it spread throughout Europe and eventually into America.

For thousands of years, wool production was done by hand. But the answer to ‘how is wool made’ changed dramatically in the 1760s with the invention of the spinning jenny. This revolutionary machine almost single-handedly industrialised textile manufacture.
Today, wool is a global, multi-billion pound industry used for everything from clothing and homewares to soundproofing and horse blankets.

So, how does all that wool come to market? How do they make wool in a factory? You – yes ewe – are about to find out.

The Difference Between Wool and Yarn

Colourful Yarn (Photo: Steven Puetzer via Getty Images)

Before examining how wool is made and answering ‘how is yarn made’, it’s important to determine some key differences between these two materials. Wool is a natural fibre that is obtained from animals, while yarn is a man-made thread or strand of fibres. Yarn can be made from a variety of materials, including natural fibres such as wool and cotton, as well as synthetic fibres like acrylic and nylon.

Wool is usually thicker and coarser than yarn, and can be more expensive. Yarn, on the other hand, is typically thinner and smoother than wool and usually less expensive.

How Wool is Made from Sheep

Sheep shearing (Photo: Peter Cade via Getty Images)

How is wool produced? The transformation from a sheep’s coat to clothing is a multi-step process, from sheep husbandry to the manufacturing of final products. The first step in the production of wool is sheep husbandry.


Every spring, sheep farmers shear their flock with heavy-duty electric razors that remove the coats in one piece. These can weigh up to an astonishing 8kg. For the sheep, shearing leaves them with a cool, thin coat for the summer months as well as aiding in parasite prevention.


To ensure as consistent an end product as possible, the wool from various bales is blended. This produces more uniform characteristics overall.


The raw, or ‘grease’ wool is then washed in a series of containers of hot water and detergent. Known as scouring, this process removes any contaminants, oils, dried sweat or ‘suint’, and dirt so it’s ready to be processed. It’s then dried. Scouring also allows for the collection of lanolin, the natural oil secreted by sheep to protect their wool. This  is extracted and taken for processing elsewhere. The wool might also be carbonised to remove burrs, seeds or other vegetable matter. This is done with sulphuric acid.


Carding involves pulling the curly wool fibres through rollers with fine metal teeth to align them and remove any residual impurities. This process also makes the fibres soft and fluffy. The wool can now be sorted in two different ways: (1) wound into a single, untwisted sliver for worsted spinning; or (2) split into narrow, twisted strips or ‘slubbings’ for woollen spinning. In terms of ‘how is wool made’, there are just a few more steps to go.


The natural product is almost exclusively white but wool is very easy to dye as it is naturally absorbent. It is submerged in boiling water with the dye and left to soak for a while and the wool will pick up the colour of the dye.


There are a number of final procedures in the process of how wool is made including fulling, whereby the wool is immersed in water to interlock the individual fibres; crabbing, which is setting the interlocked fibres permanently; and shrink-proofing the fabric, known as decating.

How Yarn is Made

Group of people knitting on sofa in living room (Photo: Betsie Van der Meer via Getty Images)

To answer ‘how is yarn made’, it’s important to determine some key differences between wool and yarn. Wool is a natural fibre that is obtained from animals, while yarn is a man-made thread or strand of fibres. Yarn can be made from a variety of materials, including natural fibres such as cotton, as well as synthetic ones like acrylic and nylon. In this instance, we’re examining how it’s made from wool. Wool is made into yarn by spinning. There are two main types of spun wool:

  • Woollen yarn: Woollen spinning generates thicker yarns with a looser weave, ideal for knitting.
  • Worsted yarn: This produces thinner, finer yarns with a smooth, tight weave, perfect for making clothes such as suits and scarves.

Preparing For Spinning

The wool slubbings do not require any further preparations and can go to the spinning phase. However, there are a few extra steps before wool can be worsted. First, the wool sliver is stretched and aligned by being passed through a narrow tunnel of metal teeth in a process called gilling before being combed between fine-toothed rollers. This removes short fibres and any remaining contaminants. It’s then flattened even more, making it into a fine sliver known as a roving. Only then can it be worst-spun.


Ring spinning is the most common method of spinning yarn. It is a continuous process that uses a ring spinning machine to twist together fibers to create a strand of yarn. Ring spinning machines are composed of several parts, including a spinning ring, a traveller, and a spindle. The spinning ring is a hollow metal ring that the traveller moves around. The traveller is a small metal disk with grooves on its surface. The spindle is a long, thin rod that is attached to the traveller and is used to twist the fibres together.

First, the spinning wheel is used to twist the fibres together to create a single strand of yarn. This strand is then wound onto a bobbin or a commercial drum. Plying the yarn is the next step in the process. This involves taking two or more strands of yarn and twisting them together. This creates a stronger and more durable yarn. The last step in the process is finishing the yarn. This involves adding a twist to the yarn to help keep it from unravelling. This also adds a softer feel to the yarn.

Weaving and Knitting

At this stage, the yarn is ready to be sold and turned into anything from skirts, scarves, suits or socks. Or it might be turned into sheets of fabric for fashion designers to create the latest catwalk designs.

Wrapping Up

Keeping cosy with a knitted sweater and scarf (Photo: IAN HOOTON/SCIENCE PHOTO LIBRARY via Getty Images)

That’s enough bleating for now. We’ve wrapped our heads around various topics in the field of how wool is made, answering everything from ‘how do they make wool in a factory’ to ‘how is yarn made’. Time to count sheep.


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