On the Subject of Sweaters, Part 3: Yarn Selection and Substitution

This post is Part 3 in a series of weekly posts I’ll be doing on the process of sweater knitting: not exactly the nitty gritty details and techniques, but the opportunities and decisions you may encounter on the way to getting a knitted sweater that works for you.

If you were to talk with a knitter who has been knitting for longer than the past decade (you may well be one of those knitters, in fact), one of the biggest differences they are likely to comment on about then and now is the kind of yarn selection available. The world of yarn retail has exploded in the last few years, and both local yarn shops and online retail venues are going strong. Yarn might come to us from larger, mainstream companies, as easily as smaller independent dyers. There are a lot of really, really fantastic yarns out there. I mean, there are A LOT of them, and if you were to take a comparison to the kind of yarn selection that was available 20, 30, and certainly 100 years ago, you would be playing a very different ball game. As contemporary knitters we are furnished with a large amount of possibility.

Most of the time this is a pretty good thing – more yarn means more choices, more colours, more fiber blends and different kinds of fibers, and more people selling yarn usually translates to more knitters being able to access yarn, so basically, hurray for more yarn! On the other hand, more choices mean it can also be harder to make sure you are matching up the right pattern with the right yarn. The knitter today has many options available, but is also in charge of many more decisions at the moment of choice.


The easiest approach – or perhaps, the likeliest path of least resistance – is to buy the same yarn that was used to make the sample of the pattern you purchased. If the sample was successfully knitted with that yarn and looks good, then chances are it was selected with some amount of care and purpose, so you can bet that your own finished product stands a good chance of success if you use the same stuff. Most commercial patterns indicate the specific brand, weight, and fiber content of the yarn used to knit the sample, and some will actually be distributed through the same channels as the yarn. (I.e. the yarn stores that carry the yarn will also carry patterns distributed by the same company). Magazines and books will generally list the yarns and their suppliers in their publication notes, and if you are savvy online or in your personal knitter network, you can find out fairly quickly if that yarn is supplied anywhere close to you.

On the other hand, there are a lot of reasons why you might not be able to use the same yarn: it might not be available in your local store; it might be sold out in the colour you wanted to use because everyone else is already making the same sweater in that colour; it might be available online but only if you pay exhorbitant customs fees to have it shipped from another country; it might be too expensive for you; you might prefer to knit with something that already exists in your stash. Whatever the reason, when you are working with a yarn that is not the same yarn indicated in the pattern, you are engaging in ‘yarn substitution’, and a lot of knitters do this very frequently. It’s absolutely do-able, and you can do it too, as long as you keep a few things in mind.

Yarn Substitution
If you’re substituting yarn for a pattern and are blessed with a friendly and helpful local yarn shop, chances are good that if you bring the pattern in they will be able to suggest the best and closest options for you to use. In general, though, the considerations they will make are probably at least some sub-set of the following, and I recommend using this as your mental list when you’re purchasing for a sweater of your own

1. Gauge and Weight.
Unsurprisingly, this is the first place most of us start when substituting yarns – we need to know if it will behave at a gauge that is the same or at least comparable to the gauge indicated in the pattern. Yarns are categorized according to a weight description – fingering weight, DK, worsted, bulky, and so on – as well as by the anticipated gauge measurement (number of stitches and rows per inch) that yarn will produce when in the form of knitted fabric. 22 sts over 4 inches would be assumed as a DK weight, for example. This system follows a set of industry standards, but at the same time there is variation within a single category. At that link, you’ll see that ‘worsted’ and ‘Aran’ are in the same category, which itself is listed with a gauge range of 16-20 sts over 4 inches. (If you want to have fun at your next knitting night, ask about whether people think worsted and Aran yarns are the same thing, I dare you).

Because a lot more publications and designers are aware that yarn substitution is very common, they will often specify this in the pattern notes: “Use Cascade 220 Heathers, or your preferred worsted wool yarn,” for example. If they’ve done you the helpful step of indicating the yarn weight, you’re good to go off in search of that. If not, have a quick check on the indicated gauge and yarn notes to try to deduce this.


In any case, most commercially available yarns will indicate on their ball band what gauge it is intended to be worked at, and this will usually include a small range of gauges and needle sizes (because this is often a little more art than science, and knitting to a specific gauge is a human activity that varies a great deal), to give you an idea of that yarn’s weight classification. (Incidentally, as a side notes if you’re curious about what all the laundry symbols on ballbands mean – and to be quite honest, sometimes one will appear that I have no idea about – here, let me help you with that.) If in doubt, read the ball band.

2. Fibre content
If you’ve honed in on a yarn (or a number of yarns) whose gauge is at or close to what you need, the next step is to ask yourself what fibre the yarn is made of: i.e. is it wool, alpaca, wool/alpaca blend, cotton, wool/cotton blend, wool/silk blend, etc. If you can help it, try to get a yarn that is the same fiber content as the one used in the pattern sample, or close to it. The reason we need to ask about this is because fiber content will tell us a great deal about how the yarn will behave. In the photograph below are three yarns plucked from my stash earlier this afternoon – the first two are earmarked for sweater projects for me this winter (you can feel free to hate me that I have enough stash that I can do that, I’ll understand. What can I say, yarn and books are the things I collect) which would all qualify as worsted weight yarns. From top to bottom, they are Cascade 220 Heather, Berocco Ultra Alpaca, and Tanis Fiber Arts green label aran. While they could all be classed as the same weight of yarn (worsted to Aran) they are not identical in fiber content, and thus will not behave or feel identically when in sweater form.


The Cascade 220 Heathers are 100% peruvian highland wool, which, while not as scratchy as sheepy wool that is practically straight off of the farm, does feel very much like wool and is slightly rough. That rough quality, on the other hand, means it will behave a bit more sturdily than very fine wools like merino, which are much softer but also less sturdy and more quickly to pill. It will also have all the practical qualities of wool – it will “breathe”, is very warm, and amenable to use in a wide variety of garments. It also carries the risk of being felted if not washed properly, so 100% wool means hand-wash, always. (If you need to have a moment of silence for That Sweater That Got Shrunk In the Washing Machine That One Time, I can wait).

The Berocco Ultra Alpaca is made from 50% peruvian highland wool/50% alpaca, which means it will have many of the practical qualities of 100% wool – versatility, some elasticity, while also taking on some of the qualities of alpaca. Alpaca is a warmer fiber than wool, but is also a longer and less elastic fiber which means alpaca garments will drape much more easily and retain less of their original shape over time. Blending the two together gets you the best of both worlds, in a way, but means you also sacrifice some of the benefits of each. Wool/alpaca blends will be warmer and a bit softer than 100% wool, but stitch definition will be a little more flat and you can expect to keep these sweaters for slightly colder days because of the extra warmth. Garments knitted with some quantity of alpaca are expected to drape a little more than 100% wool garments, and you’ll see wool/alpaca blends in a variety of modern garments for that reason.

Finally, the Tanis Fiber Arts Aran is a superwash 100% merino wool. It has all the warmth of regular wool while eliminating most of the scratchiness. Superwash wool usually feels very smooth and wearable for folks who recoil from regular wool (unless of course they are allergic to wool – in which case I am so so sorry), because it has been treated to remove or glue down the sticky hairy scales along the wool fiber shaft that make it fuzzy (and itchy) in the first place. It has been treated this way to allow it to be machine washable without the risk of shrinking or felting, which makes superwash wool super appealing for knitters who want that practicality in their garments (or, say, thinks like a baby blanket that is likely to get washed a lot). It will also feel more comfortable when worn close to the skin than 100% wool. However, superwash wool will not behave exactly the same way as 100% wool. The lack of fuzzy scales means there is a little less loftiness to the yarn and finished fabric, so it will drape a bit more heavily than regular wool and feel a little less structured. A large, loose, boxy cabled sweater knitted in superwash wool will feel heavy and big, whereas a large, loose boxy cabled sweater knitted in regular wool will feel warm and cozy and reassuring.

These are just a few examples from the world of wool yarns – as you can imagine, there are many options in plant fibers (cotton, linen, hemp, or various blends), and luxury fibres like silk or cashmere. Ask yourself why the fiber might have been chosen for that particular garment, and try to choose something as close as possible if you can.

3. Colour
It’s a simple question, but a significant one: does the yarn you want come in the colour you want? It has to cover a large portion of your body, so if you’re going to splurge, make sure it’s in the colour you want to wear. You are not choosing from the four off-the-rack sweater colours the clothing store had to offer, you are choosing from Yarn World, and Yarn World has a lot of yarns in a lot of colours. If the sample is knitted in grey but you want red and the yarn comes in red, well by all means knit that sucker in red.

4. Cost
The bare truth of the matter is that a sweater amount of yarn is going to cost you more money than most other knitting projects you could come up with – the nearest exception I can think of is a blanket or afghan. It will also be a much larger amount of money than you are likely to ever spend on a sweater in a store, so if you’re new to this process, mentally prepare yourself for that dollar amount when you go shopping, and budget for it in advance if you have to. It is not unusual for a sweater project to cost you in the neighbourhood of $100 and up, just for the yarn. If you’re not desperate to shop immediately, keep in mind the quantity of yarn you would need in a given wait, and be smart about sales – yarn sales are the best times to buy a sweater amount of yarn, because usually it amounts to getting 1-2 skeins more for the same cost at regular price.

In general, I recommend taking a moment to learn about yardage and what is typical for a sweater in your preferred size in one or two different weights of yarn. (Here, let me help you with that.) Unlike hats or mitts (usually a 100g skein will get you a finished hat or pair of mitts) or socks (most women can get a pair of socks with 100g of fingering weight yarn), yardage numbers for sweaters are not universal at all. This is useful information to have on hand if you’re at a sale, or at a fiber festival where you might not get the same yarn again.

Finally, probably the most useful tip I can give you about buying yarn and estimating quantity is a fairly common one: buy an extra skein. If you think you’re going to need seven skeins, buy eight, but keep the eighth one un-wound and un-touched, and tuck it away with the store receipt from when you bought it. That way if you don’t end up needing to use it for the sweater, you can still return it for store credit if you want (most yarn stores will allow you to do this if the yarn is in original condition and comes with the receipt). If you lose the receipt and can’t return the extra, the worst that happens is that you spent a little bit more on yarn and now have extra to make a hat or pair of mitts with. The worst that can happen if you don’t buy extra is that you end up with a sweater that has a front, back, and one and a half sleeves and never got finished because you ran out of yarn.


Gauge swatches and why we need them
Finally, on the subject of yarn: if you truly want to be sure about how it’s going to behave and whether you can work with it at the gauge you need to get, knit a little gauge swatch. Once you’ve gotten your fabulous yarn home and have thought about your pattern size and fit (see previous post in this series), allow yourself the time to knit, wash, and dry a swatch, and this will more likely than not give you some helpful information about how the yarn behaves. (Incidentally, Laura Nelkin just did a blog post about this, with helpful photographic demonstrations).

There are a lot of guidelines out there about how to knit a gauge swatch, but generally speaking, what you want is a sizeable enough square of fabric that will lie flat, which will allow you to take a gauge measurement of at least 4 inches both vertically and horizontally. Ideally the swatch should be even bigger than that, since the bigger the swatch is the more likely it is to mimic the fabric characteristics of a full sweater. (There’s an oft-repeated Q-and-A about swatches that goes something like this: Q: “Do I have to knit a swatch?” A: “No, only if you want the sweater to fit.”) If you knit a swatch, then wash it and allow it to dry, you will be able to take a gauge measurement and also understand whether or not the fabric changes at all between knitting and washing. The truth of the matter is that the only absolutely accurate gauge swatch is a full garment, because only once it is in the full shape, size, and drape of a completed garment will it actually behave like a completed garment. However, swatches are still the best tools we have to examine our gauge, and the behaviour of the yarn, to give us our best estimates before proceeding. Or, like Stephanie says, maybe they’re just little sacrifices we make to the yarn gods to help us with a successful project. Either way, I’m going to err on the side of swatches and keep making them.

The central swatch in the photo above, incidentally, is one I made for the sweater I’m working on right now, where I changed needle size halfway through the swatch (to see what would happen), and I left little masking tape notes on the dried swatch to remind me how they were different in gauge and needle size. I don’t manage to be this finicky on every swatch, but it’s super neat when I do manage it. Find a way of tracking gauge notes that works for you, so you can remember what information you learned from your swatch.


Phew! That was a lot of yarn chatter, and even still, I probably could have said more. There is always more, it seems! Next week’s post in this series will be a bit lighter (I think), and will be on the subject of working through the pattern and some things to keep in mind there. I’ll close out with a few resources on yarnly subjects (feel free to suggest others in the comments!) and look forward to seeing you all next time. Happy sweater thoughts!

More Resources

Clara Parkes’ The Knitter’s Book of Yarn and The Knitter’s Book of Wool are two of the most valuable books on the recent market, not just for the pattern collections but for the information about how different wools and fibers are processed and behave in knitted form. They are books I would recommend to anyone.

Amy Singer’s No Sheep For You is one of the few books in the knitting market with patterns and yarn information specifically for non-animal fibers. If you have a wool allergy, live in a warm climate, or simply choose not to work with wool, this is a valuable resource for you.

Ann Budd’s Handy Guide to Yarn Requirements is a pamphlet containing yarn yardage estimates for different garments to fit different sizes, and is often available in yarn shops. It can help you decide how much yarn you need for a sweater if you are lost and need a quick estimate while in a shopping situation.


  1. […] the next installment of this blog series, I’ll talk a bit about yarn, yarn subsitution, and (gasp) the dratted gauge measurement. […]

  2. Great post, I love this series! Of course I am wondering about the one picture you didn’t describe, what is that lovely Fair Isle pattern on the top swatch in your last photo? It’s gorgeous!

  3. I usually have to substitute yarn because of the rural area in which I live …..the nearest lys is an hour away. Sometimes I prefer to use handspun instead I just try to get the gauge, weight and fiber content ( because silk and wool behave very differently) close.

  4. Thank you so much for doing this series. I’ve only knitted small projects to date (socks, hats, mittens, cowls, shawls) and was just starting to think I might want to try my hand at a sweater. These posts have been very helpful and informative. And timely.

  5. I’m really enjoying this series! Next to actually knitting sweaters, I love reading about them. Or did I mean that the other way round?

    I’m guessing the last two swatches were for garments to be knitted in the round? I remember techknitter wrote about a really cool method for swatching in the round without long floats or shaggy ends.

    Oh and for those who hate swatching, I humbly and modestly present my brilliant idea 🙂 ….
    … L-shaped swatches! Blogged here: http://limescented.wordpress.com/2012/08/18/l-shaped-swatches/

  6. This is a very helpful post! Thank you!

  7. […] weekly series about how to navigate the many decisions that knitters make when knitting a sweater. On the Subject of Sweaters: Part 3 is about choosing & substituting yarns. I have such a crush on these swatches, which, for you […]

  8. Gerda Miranda · ·

    Please, unsubscribe me from your post. Thank you.

  9. Hi Gerda – You are always welcome to change your email subscription settings at any time. This is however a step that you must make yourself.

    You may do this one of two ways:
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  10. Thank you again this series is a great help.We have lovely wool down here but some how our DK must be slightly different as most wool bands say 4mm needles so I seem to be swatching pulling undone and swatching again! but I shall keep at.

  11. This was an awesome post. It honestly never occurred to me that something has to *happen* to superwash wool to make it washable, and that that might actually make a difference to other things besides its wash-ability! You are excellent.

  12. Hey thanks, Gwen! I’m so glad I could lay some new knowledge on ya 😉

    If you want to really bring this home, next time you’re with your yarn stash or in a yarn shop, hold a skein of 100% wool (the woolier and sheepier the better) in your hand and bounce it up and down in the air, and notice how it feels in your hand when you catch it. Then, do the same thing with a skein of Superwash wool. It will TOTALLY drive home the difference between these two fibers. Both wool, but not the same at all!


  13. […] and decisions you may encounter on the way to getting a knitted sweater that works for you. Previously, the topic was yarn selection and […]

  14. “More money than you’re going to spend on a sweater in a store?” I guess that would depend on what yarn you use, what stores you visit, and what size you are. You’ll have a hard time finding a good-quality sweater in a nice fiber (if I don’t want to knit with acrylic, I don’t want to buy in the store either!) and with a flattering design for less than $100. Now, unless I’m deliberately choosing the most expensive yarn out there, I never pay that much to knit a sweater in, say, 5 or 6 skeins of Cascade 220. In addition, when you’re buying yarn you pay for the actual amount of yarn you need to cover your body, whereas in stores the price is typically the same for all sizes so the small sizes “subsidize” the bigger sizes.

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