A lovely reader asked about super twist yarn in one of my last posts, and what makes it different. I thought her question benefited a post of its own, so here it is!
To address super twist sock yarn then, and how it is different to other sock yarns and yarns that you might normally choose for a garment or shawl:
This is a super twist yarn. (For the purposes of this post, I’ve used my lovely stash of Knitsch Yarns Sock to illustrate the point).
Can you see how the yarn looks almost ropey? That’s because the twist in the yarn is tight. Super twist is invariably a two-ply yarn, and spun very tightly, to literally ‘super twist’ the yarn. The spinning process has created a yarn with many more twists per inch than a “regular” yarn. When spun this way as a 2 ply, it creates a yarn with a massive amount of coiled stretch, making is very suitable for things that need to be stretchy, and not go out of shape (like socks, hats, fingerless gloves or fitted cardigans). It has been balanced, so if you are thinking that it might coil back on itself like some tightly spun single ply yarns, you can be assured that it will not.
If you gently pull a strand of super twist yarn between your fingers, you can stretch it out a lot further than regular yarn used in garments. Even holding the skein in your hand will give you a feel for the amount of energy stored in the yarn – it will feel much more ‘alive’ and bouncy than a skein of ‘normal’ yarn. This factor makes it singularly comfortable to knit at tight, sock gauge (and therefore my favoured sock yarn), because the yarn will “give” under your fingers when being knitted, and will not stress your hand joints. When knitted, the resulting fabric wants to pull together and stay tight, and not go out of shape after a time. It creates a dense, strong fabric that is perfect for socks! It also gives good stitch definition for cables, like this one below. This is what gets me very excited about super twist yarn.
The density of the twists also makes a normally delicate yarn (100% merino, and only two ply) into something much stronger, which resists wear and tear very effectively.
Below is a typical 3 ply fingering yarn used for garments and things like shawls. The twist is much more relaxed, and if you pull this strand, you will get no stretch or bounce. It is perfect for stunning lace shawls and other garments that do not need to be ultra stretchy. (The below picture is one of Anna Gratton’s beautiful 4 ply 100% wool yarns.)
Here’s a side-by-side comparison of a garment-purpose fingering yarn and a super-twisted sock yarn. Can you see how the super twist is much plumper and springier looking?
So how is ‘super twist’ different to other sock yarn? Super twist is 2 plies in a strand, and most normal sock yarns have 4 plies. The below images shows 4 ply sock yarns next to a super twist.
In most cases, sock yarns have many more twists per inch than a garment-style yarn, which does make sock yarn in general much stronger, more durable and stretchier than other yarns. The addition of nylon, a regular component of many sock yarns, also gives it added durability. Nylon can also make up for lack of strength in sock yarns that are not tightly spun.
For a detailed explanation of ply and twist, have a look at this excellent article by Clara Parkes.
Watch out for Secrets of the Socks, Part 2: making socks fit your foot and look good.