***I originally wrote this post for the Urban Yarns Blog on September 14, 2014. It is reproduced here with permission.
Today we’re going to chat a bit about yarn construction, specifically the significance and meaning of different types of plied yarn.
First off, I want to put to rest a common misunderstanding: the number of plies in a particular yarn has no inherent bearing on its gauge. That is to say, you can have a single-ply laceweight yarn, a single-ply bulky yarn, a 6-ply fingering weight yarn, an unplied worsted weight yarn, etc…
The concept of plies corresponding to gauge was at one point something of an industry standard, but modern manufacturers have since moved away from this. Historically, there was a standard-ish base, unplied weight for a single strand of yarn, so that (for example) a 4-ply yarn (made from four individual strands spun together) would be roughly the same from mill to mill to mill. This can be still be seen in some manufacturers labelling yarns as 4-ply (which corresponds to fingering or sock weight) or 6-ply (comparable to sportweight), but that is about as far as it goes.
So! For modern yarns, plies are independent of gauge. This really isn’t a big deal, as pretty much every manufacturer lists the gauge straight on the yarn label.
For todays discussion I grabbed a few yarns out of stash to take a look at. We have some single-ply, 2-ply, 3-ply, 4-ply, and…. other. Yeah, some yarns are a bit more special – we’ll talk about them later.
The single-ply yarns we have here are Schoppel Wolle Zauberball (lace weight) and Noro Kureyon (worsted weight). You can see that they are both constructed of a single strand of yarn, which is composed of many individual wool fibres that run parallel to each other. Both of these yarns have a light to moderate twist and are relatively soft in the hand, but you can see that the red Kureyon is much hairier and less densely spun than the smoother, tighter Zauberball.
The two-ply yarns I chose are Harrisville Designs Highland (Aran weight), Koigu KPPPM (fingering weight), and Rowan Kidsilk Haze (fingering/laceweight). These three yarns are composed of two plies of yarn spun around and around each other. The Highland and the KPPPM are both 100% wool and have a relatively smooth surface compared to the Kidsilk Haze which is mohair and silk, and in which each ply is composed of a silk core, with the mohair spun more loosely into and around it, giving the unique “haze”. You can also see that the KPPPM has a very tight twist compared to the more relaxed Highland and Kidsilk – I’ll talk more about that later.
Next up, the three-ply yarns are a mystery acrylic yarn from deep in my stash, and Habu A-21 Silk Stainless Steel. This really shows the possible range of gauges available from the same number of plies. It’s a bit tough to see, but the Habu has two plies of silk, and one of an ultra-fine stainless steel all spun together.
Four-ply yarns! We have Cascade 220 (worsted weight) and Madelinteosh Merino DK (DK weight). These are actually quite similar, but a distinguishing factor is the tightness of the spin – you can see that the plies of the Madelinetosh spiral around each other much more tightly than the Cascade. You might also be able to tell that the Madelinetosh looks smoother – it is a superwash yarn and has been treated to smooth the surface of the individual yarn fibres to prevent felting.
Finally, we have some unique constructions. First up is a mystery novelty yarn. It seems to have five or six plies, all made of a different fibre. Next is Habu Merino 4P. The Habu is really interesting, as it is four plies of merino (and each ‘ply ‘ is actually a 2-ply strand unto itself!), which are not spun together, but are wrapped with a very fine two-ply silk thread. So this is technically a 10-strand yarn that is a light fingering weight!
There are several other unique constructions, and if there is enough interest, I might take a closer look at some of them for you!
So, what does all this mean, other than numbers are kind of meaningless? Well, as a general rule, the greater the number of plies, the more durable the yarn. This means plied yarns will pill less than unplied yarns, and generally wear better. So socks or other high-wear items are best worked in a plied yarn. Similarly, the tighter the twist in a yarn, the more durable the fabric will be.
The flipside is that a looser plied (or unplied) yarn fabric is often a bit softer in feel (and in wear). Now, I haven’t tested this, but it also stands to reason that a loosely, or unplied yarn will felt easier than a tight, high-ply yarn.
A more tightly plied yarn will also produce a fabric with different drape and gauge than an unplied yarn, and a really tightly plied yarn might start to twist and loop back on itself while you work with it. Also, smooth plied yarns tend to have better stitch definitely than unplied hairy yarns – so choose wisely when working something with a lot of detail…
These are all simply factors to consider. There is no perfect yarn, only yarns that are more or less suitable to a specific project. This information is best absorbed through experimentation, so it’s great if you can learn to identify different types of yarn construction, and play with using them in different ways in your work.
Now, I know this is a lot of information to take in, which is why we would love to help you pick out the best yarn for your next project!