I am a sock knitter. I haven’t left my house without a sock in my bag for thirty-five years, and I even did my Master Spinner in-depth study on spinning sock yarn. That in-depth study taught me a lot and I have some strong opinions on what constitutes a good sock yarn.
In 2006, I did a Master Spinner in-depth study on designing sock yarns. These twelve sample socks represent several choices we can make when we choose sock yarns. Some yarn samples fared better than others, leading me to some conclusions about what to look for in a yarn that will make great socks.
There are a lot of yarns on the market right now that are labelled sock, but that label does not necessarily mean they are great yarns to make socks from. Sock has become a popular description for a weight of yarn that ranges from fingering weight to light sport weight, but some sock yarns are superior to others when it comes to knitting actual socks.
Putting the word sock on a label does not necessarily mean the yarn is suitable for making socks that are comfortable and durable. These Canadian sock yarns will all make durable and comfortable socks, but each yarn has very different characteristics
Of course, you can knit socks with any yarn you like, and they will be wonderful. But depending on how and where you wear those socks, sometimes they don’t stay wonderful for very long. You may wear through the heels or toes, the socks may grow in size until they are floppy and uncomfortable, or worse, they may shrink in the first wash. Some socks may turn out too warm or too thick for daily wear, others may not keep your toes warm enough. After thirty-five years of knitting socks—and lots of failures—I’ve learned that there are some features we should look for when choosing a yarn, that can help us make comfortable socks that will last.
Fibre Content
When we think of knitting socks, most of us automatically think of wool, and with good reason. Wool is versatile and readily available. Wool is flexible and naturally elastic, so the socks we knit will hug close to our feet and not lose their shape. Wool is insulating to keep our toes warm but breathes to help prevent our feet from sweating. And if our feet do sweat, wool will wick the moisture away from our feet and keep them dry.
A lot of commercially made socks are made from cotton, bamboo rayon, or 100% nylon. These fibres make a much lighter-weight sock and are much cheaper to produce industrially, but these socks are made to be disposable for the fast-fashion market. Sturdier wool socks are also made commercially, and while they tend to be pricier than their nylon counterparts, they are relatively durable and have the qualities that I mentioned above.
Most of the sock yarn on the market for knitters is wool. But not all wool is equal.
Some breeds of sheep make wool that is better suited than others for the rough wear that socks are subjected to. Wool from longwool breeds, like Romney and Blue-Faced Leicester (often referred to as BFL), is strong and less likely to break in a yarn than Merino wool. Many sheep breeds that are grown primarily for meat, like Suffolk and Dorset, also produce excellent fibre for sock yarns. Fibre from these breeds tends to be both moderately coarse and highly crimpy, making it ideal for sock yarn. Even though the market is flooded with Merino sock yarns, Merino wool alone is too fine and tender to make durable socks.
This is where the fibres I like to call “add-ins” come into play. A yarn made only with fine Merino wool will quickly wear thin due to the abrasion that happens when our feet rub against our socks, and our socks rub against our shoes (or the floor). The individual fibres may break and tangle, causing pills on the fabric. But if we blend in another fibre like nylon, that added fibre will lend the fine Merino some strength and durability. This is why the vast majority of yarns labelled sock yarn contain some amount of nylon—usually between fifteen and twenty percent.
While nylon, which is sometimes labelled polyamide, is the most common added fibre in sock yarns, some mills have started using bamboo rayon. However, both of these fibres are synthetics that eco-conscious knitters might prefer to avoid, leaving them looking for more natural blends. Two natural fibres that can add strength to sock yarns are silk and mohair, but each of them add very different characteristics to the yarn. Nylon and bamboo rayon are solid with no separate core or surface layer; they are very fine but far less flexible and insulating than natural fibres. Silk and mohair have the advantage of being both flexible and insulating, making the sock that little bit more comfortable. The disadvantage to silk and mohair is that they make the yarn a little more costly to produce and purchase.
Adding another fibre to wool makes a stronger sock yarn. The sample at the left has added nylon and feels stiff and crisp to the hand. The centre sample has added silk, and the sample to the right has added mohair. Natural fibres tend to feel smoother, softer, and more flexible, suggesting they will feel a little more comfortable against our feet.
Whether synthetic or natural, the addition of these second fibres has another benefit as well—they help make the sock more washable. Each of the fibres I’ve listed has a relatively smooth surface, and thoroughly blending those smooth fibres between the wool fibres will reduce the contact between wool fibres. The surface of a wool fibre is covered in small scales, which form barbs. Shrinkage happens when these barbs become tangled with each other and pull the fibres closer together, so, if we put a smooth fibre between the wool fibres, there will be less tangling and less shrinking.
Of course, using these fibre blends does not guarantee that socks will not shrink in the wash, which has led to the popularity of super-wash yarns. There are a few different super-wash processes, but the end goal of all of them is to eliminate those little barbs on the surface of a wool fibre. Depending on the process, this is either achieved by burning the tips of the scales off with a caustic solution, or by coating the fibres with a polymer to smooth the tips down. And depending on the process and the degree of processing, this can lead to problems when we knit socks with this yarn. Removing the tips of the scales reduces the likelihood of those fibres tangling together, but it can also potentially make the fibres slip away from each other. As those fibres slip apart, the sock will lose its elasticity and stretch out, becoming loose and floppy. It is a good idea to always swatch before you use a new-to-you sock yarn, but it is especially important when that yarn is super-wash. (Clara Parkes even recommends hanging that swatch with a light weight to check to see if the fibres will pull apart and grow the swatch.)
Superwash wool will add loft and softness to a sock yarn (left) compared to non-superwash wool (right), but the superwash yarn may compact or “grow” when washed. It’s always a good idea to swatch and test the yarn to see how much it will change after we wash our socks.
Yarn Structure
When we look for a yarn to knit socks, the structure is probably even more important than the fibre content. With the right yarn structure, even fine Merino can make more durable socks.
Worsted-style yarns are smoother and stronger than woollen-style yarns, which will help our socks last longer (read more about the difference). The less parallel arrangement of fibres in woollen yarns means that there will be small ends and loops of fibre loose at the surface, and those bits of fibre can lead to the pilling and breaking of the fibre, something that we want to avoid in our socks.
Woollen-spun yarns can make warmer socks than worsted-spun, but they will not always be as durable. The woollen-spun sock on the left will be more prone to abrasion and pilling than the worsted-spun sock on the right.
When we knit socks, we need to use a plied yarn. A singles yarn can be labelled sock to describe its weight, but singles are not durable enough to survive the beating that socks take; socks made with singles yarn will wear thin at the heels and toes very quickly. There are some exceptions, but I consider it a good idea to just skip the singles for socks.
Some mills will offer a two-ply sock yarn, but the optimum number of plies for durable and comfortable socks is probably three or four. Two-ply yarns may abrade at the point where the two plies intersect and make a worn spot in your sock, but three- or four-ply yarns will have a smoother and rounder surface that will not abrade as much. The round structure of three- and four-ply yarns will also make a smoother surface on the cloth of our socks, so the socks will feel more comfortable on even the most tender tootsies.
For me, the real marker of a good sock yarn is the amount of twist in the yarn. The more twist, the stronger the yarn; a stronger yarn will be more resistant to abrasion, and your socks will (theoretically) last longer.
There are two ways to add more twist to a yarn: by twisting the fibres more or by adding plies. When we add more twist to each single and then ply three or four of them together with the appropriate ratio of twist, we make a stronger, denser yarn. The fibres will be pressed closely together, which prevents them from rubbing against each other and breaking.
Both of these yarns have 3 plies, but the sample on the left has a little more twist in the singles and ply, making the yarn denser and less prone to abrasion than the sample on the right. The sample at the left has added more twist to compensate for the softer Merino fibre, the sample at the right can be durable with less twist because it contains a stronger wool, and mohair fibres.
Alternatively, we can spin singles with a lower amount of twist and then ply several singles together. As we add singles, we are contributing the amount of twist in each one to the finished yarn. As we add more singles—usually to total 6 or 12—we are pressing those singles closer together and adding strength and smoothness to that yarn.
As we add more plies to a yarn, the yarn becomes less prone to abrasion and will make more durable socks. A 2-ply yarn (left) will wear thin before the 3-ply (centre) or 4-ply (right)
You don’t have to be a hand spinner to determine whether a yarn is high twist enough for your socks. There are two very quick checks you can do to determine whether your yarn will make durable socks. The first check you can do is to untwist a bit of the yarn and count the plies. Four or more plies will usually tell you that your socks will survive the wear and tear.
The second check is a simple tug test. Hold a small length of yarn between your hands and tug firmly on the yarn. If it snaps right away, it may be too tender for socks that will see hard wear. If it holds together after 3 or 4 good pulls, it’s probably a good choice for your socks.
If a yarn fails these tests, you can certainly still knit socks with them. There are plenty of tricks knitters can use to reinforce toes and heels, or we can take extra care when we wear and wash our socks. But choosing a yarn that we know will make durable socks—knowing that we are making socks that will endure—adds a level of ease and joy to our knitting.
The joys of using the right yarn for socks! These are currently my oldest socks, knitted in 2008. The yarn is 4-ply, high twist, and made from untreated wool and nylon. I’ve had to darn one toe, but otherwise these socks wear like they are brand new.
All images credit Michelle Boyd.
