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What Is Yarn? Yarn Types, Weights and Quality Explained

What Is Yarn? Yarn Types, Weights and Quality Explained

Trying to decide which yarn would be the perfect choice for that new knitting or crochet pattern you want to start? Wondering what’s the difference between a DK and an Aran weight ball? Feeling bewildered by the multitude of fibres available and can’t work out whether acrylic or mohair is the best way to go? The world of yarn can certainly be overwhelming at times… but at Deramores, we don’t want you feeling stressed out by something that’s supposed to bring you joy! We’ve put together a comprehensive guide that’ll walk you through everything you need to know about yarns, so you can top up your yarn stash without so much as a furrowed brow. Dive in to learn what yarn is, all about yarn weights and types, and how to choose the perfect yarn for your project. Let’s conquer the confusion for good!

What Is Yarn?

To put it simply, yarns are continuous lengths of fibres, which can range from synthetic to natural – but more on this below! – that are perfect for crafting textiles, including knitted and crocheted items!

Yarn Fibres: What Is Yarn Made Of?

You may come across the odd crafter who absentmindedly refers to all yarns simply as ‘wool’ - the truth is, the term ‘yarn’ refers not only to wool, but to all spun fibres... and the variety of fibres used to create the yarns available to us today, is vast. Broadly speaking, these fibres can be divided into three distinct categories depending upon their source. These are: animal fibres, plant fibres, and synthetic fibres. Plant fibres include textiles such as hemp, bamboo, linen, jute and cotton. Synthetic fibres are not derived from the natural world but are manmade, and include materials like polyester, acrylic and nylon. Last but not least come the animal sourced fibres; these originate, unsurprisingly, from the fleece or coats of animals (or, in some cases such as silk, from animal-produced gossamer or cocoons) and include wool, silk, and alpaca.

Typically, natural fibres require more care when it comes to handling, storing and washing, as they can be prone to shrinking or stretching, as well as more susceptible to moth damage (unless treated) than their synthetic counterparts. However, animal-sourced fibres (a.k.a wool!) are much loved for their breathability as well as insulating properties. Plant-derived fibres generally retain less warmth and possess less elasticity than wool; however, in some cases they are stronger.

As one of the most versatile fibres out there, wool’s elasticity makes it a fantastic option for a whole range of projects, from fashion, to home accessories, to stuffed toys. Of course, with so many different fleeces and coats being utilised by the yarn industry, there is a plethora of wools available, each with its own unique set of qualities. From Merino to Mohair, Cashmere to Norwegian, it can be tricky discerning exactly which wool to select for which project. If you’d like a little more information on the features and benefits of each, check out our guide on the different types of wool right here.

Of course, no fibre need be used exclusively, and it's very common to come across yarn blends created to combine the benefits of two fibres. You may find synthetic fibres blended with natural fibres to help impart strength and durability, or more expensive fibres blended with more affordable components to make the yarns more accessible. One of our favourite blends is wool and silk - two fibres that complement each other wonderfully to produce a luxuriously soft yarn that is incredibly comfortable to wear. Whilst wool is noticeably flexible, silk itself has no elasticity, but instead brings exceptional strength and a gorgeous texture to the yarn, making it a joy to work with, as well as dress in.

You can read more about the benefits of wool and silk yarns here, and discover our top recommendations for gorgeous yarn blends.

What Are Yarn Weights?

When shopping for yarn, you’ll notice that they’re not only labelled up by their composition, but also by their yarn weight. The weight of a yarn is how we indicate its thickness or ‘ply’. Generally speaking, the number of ‘ply’ a yarn has will denote the number of threads woven together to make the yarn strand; a 4-ply yarn will be composed of 4 threads. You’ll find an array of yarn weights across the spectrum from ‘super chunky’ at the heaviest, all the way down to ‘superfine’ or ‘laceweight’, at the most delicate.

Slightly less bulky than the heaviest weight yarns is Aran or Afghan yarn, followed closely by DK yarn which sits somewhere in the middle. Aran yarns are typically 10-ply (you may also find such yarns labelled as ‘worsted weight’’ or even simply as ‘10-ply’) whereas ‘DK’ stands for ‘double knitting’ and defines a yarn that has 8 plies (you may find it labelled more simply as an ‘8-ply yarn’, or ‘light worsted’). At Deramores, we recommend a chunky yarn weight or even a midweight yarn, depending on its composition, such as Aran or DK, for beginners who are right at the start of their knitting or crochet journey, as they're some of the easiest weights to learn with. For more detailed advice on selecting the perfect beginner’s yarn to learn with, check out our top tips right here.

Something you need to know when it comes to wrapping your head around yarn weights is that you’ll find that the UK terms can differ slightly from the US terms. Read our yarn weights conversion chart to know the differences between UK, US and even AU yarn weights.

Yarn Quality - How Do I know Which Yarn Is Best?

The fibres used to create yarn come in either filament or staple form. Because synthetic fibres are manmade, they are usually supplied in filaments of continuous and uniform length, as is the natural fibre, silk. Other natural fibres like wool and cotton are - in contrast - supplied in short, discrete staples, appraised by the length of a group of fibres in any given ‘clump’ or sample of fleece or fur. The quality of a natural fibre is often determined by its staple length; shorter fibres are trickier to spin than longer ones, and shorter staples result in ‘hairier’ yarns. In contrast, long staple fibres will produce softer, smoother yarns which, in turn, are favoured for the creation of superior garments and accessories.

To produce a smoother, finer yarn, a process called combing can be used at manufacturing sites, in which a comb-like instrument sorts the fibres into a parallel formation, encouraging all the shorter fibres to fall out, and leaving only the longer fibres in place for spinning.

When it comes to wool, grading is based also on the fibre’s diameter, and its crimp. The average diameter of a fibre is measured in microns, and the crimp is measured by the number of bends that occur within an inch or centimetre of fibre length. A ‘fine crimp’ indicates a fibre that has many bends and would usually be fine in diameter. Finer wool with more crimp generally lends itself better to more high-end, lightweight fabrics, and will offer a better drape than its thicker, coarse-fibred counterparts.

Yarn Blocking - Which Yarns Need This?

If you’ve ever crocheted a granny square only to be disappointed with how wonky it looked at the end, then blocking is the technique you need to know about. Put simply, blocking utilises water to help stretch and fix your finished knit or crochet piece into shape once complete, helping you to achieve straight edges, crisp uncurled corners and better-defined stitches.

If you are using a synthetic yarn you shouldn’t need to block your project; however, you may choose to block your make, such as a granny square, to ensure it is as flat as possible with no curled edges, ready for when it comes to stitching your square into a cosy blanket - the choice is ultimately yours and you'll likely choose to block projects that require flat, straight edges. If you are working with an animal or plant fibre, such as wool or cotton, blocking is a fantastic way to ensure your finished make ends up perfectly shaped.

There are a few ways to approach the blocking technique, but the underlying principle remains the same throughout...

Your knitted or crocheted fabric needs to be wetted - but not too much. Some apply water with a misting bottle, some will dampen directly then remove excess water by blotting with a towel, whereas others opt to steam their project. Choose whichever approach works best for you!

Next, the piece will need to be laid out flat onto a blocking square or board (or any flat surface that won’t be damaged by water) and pinned into place, so that the edges are held firm; manipulate your piece into the desired finished shape as you secure it. Once held in place, allow your piece to dry fully. Ideally, leave it for at least 24 hours in a warm dry spot where it won’t be disturbed, before removing the pins.

Whatever you decide to create, we've a yarn for every pattern at Deramores… and now you’ll know how to select the perfect one, for your next project!