Top 5 reasons to knit a swatch

Top 5 reasons to knit a swatch

Knitting a swatch is considered sacrosanct to some; a waste of time to others; and still others just can’t get their heads around how or why to do it. I’ve addressed the most basic aspects of how to knit a swatch before, but today I want to talk about why. Because there are more reasons for taking the time than you may have considered.

1. Meet the fabric
To me, this is even more important than the standard reason cited for swatching (which I’ve thus demoted to No. 2). Casting on without swatching is like getting married at first sight. Think of the swatching process as you and the fabric getting to know each other first. If you’re using the yarn specified in a pattern, you might find out you don’t really like it, or would prefer it knitted at a denser or looser gauge. If you’re substituting yarn, a swatch will help you know if you’ve chosen well. What about your color choice — will the pattern (and the fabric) look good in that color, or will the yarn and stitch pattern drown each other out?

The purple swatch above was for a potential Bellows Cardigan. I loved the sweater pattern and the color of the yarn, but as soon as I knitted the swatch in that color, I knew that was not a garment I would wear, so I changed course before ordering a sweater’s worth of it.

You want to know that you’ll want to wear this fabric, so knit a big swatch, and block it. Wrap it around your forearm like a sleeve. Tuck it in the back of your shirt collar and wear it around for awhile. Or if it’s for a hat, tuck it inside another hat, pressed against your forehead, and see how it feels. (And don’t forget to abuse your swatch to see how it holds up.)

You also want to know that you’ll enjoy knitting it. The swatch in the upper left is Mungo, and the one next to it is a strand of Mungo held together with a strand of Pebble, which I thought I might like even better. I did like it better, but not so much that the added expense of the second strand was justifiable, plus I discovered that it would have been maddening to knit, as those two yarns are super clingy with each other. So the second swatch convinced me to stick with the first.

2. Check your gauge (or “tension”)
The only way to know what the finished dimensions of your knitted object will be is to know how big your stitches are. If you’re knitting from a pattern, and it states finished measurements, yours will only match those measurements if your stitches are the same size as those of the person who wrote the pattern.

Stitches are the building blocks of knitted fabric.

Imagine I’m hanging out with Monique and Tessa and I build a little castle wall out of blocks. The girls want to copy it, so I tell them how many blocks wide each of my rows is, and how many rows tall, so they can replicate it. If Monique is using the same blocks as me, her wall will match. If Tessa’s blocks are smaller, she will quickly realize that if she follows my directions, her wall will be smaller. If her blocks are bigger, her wall will be bigger. Same with knitting.

Knitting patterns include gauge so you can make sure you’re building with the right size blocks. If you don’t care how big your “wall” turns out — if you’re knitting a scarf or a shawl; or if the hat, socks or sweater you’re planning to knit can turn out any old size and you’ll find someone who fits them — then maybe don’t worry about it. But if fit matters, knit a swatch, block it and measure your gauge.

3. Try out the stitch pattern(s)
Becoming a more advanced knitter means continually tackling new challenges and developing new skills. Lace, cables, short rows, different increases and decreases. These things can look a little messy on first try, or maybe you just want to see if you can do it before casting on a large project’s worth. Try it on a swatch! The swatch in the center right above is my first swatch for my Amanda cardigan, and in addition to establishing my gauge, it gave me a chance to get comfortable with some cable motifs I hadn’t done before at that point — the diamond, the braid and the honeycomb stitch.

This is also a chance to discover things you might want to know before you officially get started. That swatch was on gauge but I didn’t like how the honeycomb looked a bit cracked, so I wound up going down a needle size and liking it better. On my second swatch for it, at center left, I also decided to test whether cabling without a cable needle would impact my gauge — and boy did it! If you look closely at that center left swatch, you can see that the bottom half of the honeycomb is sort of squashed, compacted. That’s the part I knitted without a cable needle. For the upper part, I did use a cable needle and it gave the honeycomb a more natural look. So even though that’s a ton of cabling, I had to make the commitment to do the entire cardigan with a cable needle — and I’m glad I knew that beforehand.

Likewise, if you’re doing colorwork you may simply want to practice first — but you might also find your colorwork gauge is different from your single-yarn gauge. So if you’re knitting, say, a sweater with a colorwork yoke and a solid-color body, you may need to use two different needle sizes to get the same gauge across those two different fabrics. (Many knitters need to go up one needle size for colorwork.)

4. Do your own math
If, like in the cable example in No. 3, you consciously decide to knit at a gauge different than pattern gauge, then knowing your gauge (the size of your stitches) in comparison to the pattern gauge is the way to control the outcome. Going back to those building blocks, once Tessa realizes her blocks are smaller than mine, she can choose to stick with my numbers and let the wall be smaller. If she wants to know how much smaller before committing, knowing the size of her blocks and mine will allow her to calculate that. If her blocks are half the size of mine, her wall will be half the size. If, on the other hand, she likes the look of her smaller blocks but wants to use them to make a wall the same size as mine, again, knowing the size (the gauge) of her blocks is the key. If her blocks are half the size, she’ll need twice as many. Or she might decide to build a wall like mine but to her own preferred measurements, which she can easily calculate if she has simply measured her blocks. If each block is 4″ wide and she wants to build a 20″ wall, she’ll need 5 blocks per row. Just like stitches! (Of course, if there’s a stitch pattern involved, you always need to keep its multiple in mind. E.g., a 6-st cable that repeats across the fabric would require a stitch count that’s a multiple of six.)

5. Buy enough yarn
There’s also the matter of yarn math. Pretty much every swatch I’ve ever knitted for someone else’s pattern has come in at tighter row gauge than theirs. If my building blocks are shallower than theirs, it will take more of them to reach the same height, right? If it takes me more rows to fill in a sweater than it did for the pattern creator, I’ll also require more yarn than they used. So again, you want to know a thing like that before you get started.

. . .

These 5 cases are largely focused on situations where you’re knitting from a pattern, but of course if you want to knit from an idea in your head, a swatch is the starting point. Swatching is a way to figure out what sort of fabric a given yarn might want or be willing to be. (“What happens if you hold two strands of Pebble together and try to cable with it?” See second-from-bottom swatch above.) And once you’ve knitted your yarn into a fabric that feels right for it, what sort of object does that little square of fabric want to become?

A swatch gives you the power to go your own way.

For lots more great tips, see the comments below.


PREVIOUSLY in How to: How to knit an adult cardigan at child size

32 thoughts on “Top 5 reasons to knit a swatch

  1. One more suggestion: once the sweater is under way, tuck the swatch in your purse so you will have it with you when you are shopping so you will have it available when you are looking for those perfect buttons, or you think you see just the right top or pair of pants to wear with it. Saves a lot of time by keeping you from returning unfortunate purchases.

    • Even better if you think to knit a buttonhole in your swatch! That never occurred to me before …

  2. So many really good reasons, but like a lot of knitters, I frequently cheat. I’m less likely to bother if the wool is one I’ve worked with many times before. If I’m knitting a bottom-up sweater, I’ll often use the sleeve as a swatch (yes, I’m aware that gauge in small diameter circular knitting can be tighter than normal). In a top-down circular sweater, I might choose to guess on the size to knit, then adjust during the increase process to accommodate any gauge discrepancy. If there’s a pocket lining, I use that as a gauge in stocking stitch. You get the picture. That said, if I’m designing an aran sweater, I’ll do a full-on extra-wide, extra-long swatch, then wash and block it and measure when dry. There’s too much work in aran stitches to risk having to do a makeover down the road.

  3. I have another, only because I forgot to do this, knit your swatch with all the colors you are going to use! Then wash it to see if any bleed!

      • Oh, I learned the hard way on this one. Thankfully, it was only a shawl, but I was still very choked when my finished tri-colour yarn project turned out a different colour than the one I envisioned the whole time I was knitting it. But, it was an excellent lesson about not ‘trusting without testing’ that a yarn won’t bleed simply because it looks just like another one that you know doesn’t run. Although my heart still sinks a smidge every time I pick up the shawl, I love it for the warmth and comfort of the two beautiful yarns that surround the one that gushed it’s burgundy colour all over them and keep it close as an excellent reminder of a valuable lesson learned that I don’t intend to repeat!

  4. The “check your gauge” mandate moved to second place with the “new” #1 makes total sense to me: get to know your fabric. Yes! Felt like a light bulb went on. Thanks!

  5. Great information!
    I have a question. Should a swatch ALWAYS be blocked? Some patterns will give guage and say blocked, and some patterns will only give guage, leaving me guessing as to whether that means blocked or unblocked.
    And, if you block a swatch, can the yarn be used after it had been blocked, if you need to unravel the swatch and use the yarn?

    • You should always treat your swatch however you’ll treat the finished object. Unblocked gauge is essentially meaningless unless you’re never going to wash the FO. So regardless of what the pattern writer may have done regarding blocking, if you want to match their stated gauge and measurements, and you’re going to wash your FO, wash your swatch and measure that.

    • I’ve unraveled a blocked swatch before, when I’ve needed that extra yarn. No problems yet, but I think it depends heavily on the base. I wouldn’t expect a mohair/silk yarn to unravel easily, especially after blocking.

  6. Such an important post. It only took me one sweater that grew after blocking, to teach me to block the swatch.

    • This is another good point. I don’t tend to knit with fibers that grow, so I’ve never actually taken this advice, but I have heard it said that if you’re knitting with something that might — like alpaca or bamboo or tencel, or a blend — then your best bet is to knit a really big swatch (or the lower half of the body or something in that realm), block it, and then *hang it* for a few days before measuring it.

  7. It’s also done to see what you need to know about caring for the garment in terms of cleaning (hand vs. machine wash, etc. as well as what happens if it’s a garment being worn (hang up the swatch to see how the length grows when it’s worn.

    • Oh ha — I should have read your comment first! (I just said the same thing in a reply right above.)

  8. I should add: I recommend waiting at least a day or two after a swatch feels dry before measuring it. Fabric will tend to still contract in some cases and you don’t want to measure too soon.

  9. Always good to measure and record your gauge before AND after blocking. That way you can compare your actual knitting to the pre-block gauge to see if you are still on track.

  10. All good reasons! I have probably already shared the conversation I had with my sister one day, when she asked me if I swatch before making a sweater. “Only if I want it to fit!” was my wise acre answer. We then proceeded on with “What do you do if you can’t get gauge?” and the various options, ending with, if I really like the fabric I do the math to determine how to change the numbers to get the sweater I want. That received a horrified “you do the math for the WHOLE pattern?”

    She was in the middle of a sweater that had gauge trouble,s so she took a chance and cast on a different size. It still isn’t done yet, so I don’t know how that worked out out for her.

    I still swatch and wash the swatch. Never tried a buttonhole on one, but I am going to next time!

    • I tend to buy the buttons first, while the knitting is underway, and then swatch to make sure that I have a buttonhole that I like that works the button I fell in love with. The button I love may not be the size called for in the pattern, and the buttonhole required for that button may take awhile to determine. But I always swatch the buttonhole, using whatever stitch I think I want to use for the button band. (sometimes that changes as well; fidelity to the pattern isn’t really my strong point); it doesn’t take long to swatch a bunch of buttonholes, but in my mind, it can be the make or break point of the sweater so its worth it.

    • I picked up from other knitters that, if you are working from a graded pattern, you can “knit L to get S” kind of thing. No math. It has worked quite well in most cases.

      • You can, sometimes. Though I still maintain that you should do SOME math even when doing that, to be sure that L will give you the size S you need.

  11. I do know the value of a swatch but I often need to know several swatches before I get the right needle, etc… And I know that what the needle is made of it really important as well. But I seem #foreverstuckinswatchworld!

  12. This is a great article and the comments are awesome! When I teach knitting to my beginning knitting students I always teach by making a “swatch”. In the swatch we practice the techniques of the pattern, and the bonus is they learn what their gauge is and if we need to adjust.

  13. What if you’re gauge changes? The last sweater I knit (bottom up) ended up being longer than expected because my row gauge had changed: the swatch was knit with the same needles, and worked flat, just like the sweater. I had 28rows/4″ in swatch and 24rows/4″ on the sweater!
    More recently I knit a pair of colorwork mittens: I started knitting the second mitt 4 months after I’d finished the first and ended up with a mitten 1-2 inches longer!
    I’m a loose knitter, and often have to go down a needle size or two to obtain gauge, but my row gauge can be “unpredictable”. Any suggestions?

    • My gauge also varies a lot from day to day, how life is going, etc. I now obsessively measure, both the gauge (am I still getting x many stitches per inch, y many rows per inch? do I need to change anything?) and the item as a whole (is it really 24″?) If a yarn changes a lot after washing you’ll need to know how to account for it, but that hasn’t been much of a problem for me. I had this happen to me the other day. One sweater, two sleeves, same row count, one sleeve an inch longer. I handled that on the next sweater by knitting two sleeves at a time/magic loop. Not my preferred technique, but it worked out well in the end, so it may become my standard.

      I’m also very willing to rip out and redo. I would much rather redo than be unhappy in the end. Since I’m definitely a one-project-at-a-time knitter, it doesn’t tend to lead to projects stalling in WiP-land.

    • I also have a lot of trouble with this! I finally realized that a lot of it for me is that the weight of the finished sweater changes things quite a bit compared to the swatch I knit, even if it’s a larger one. The weight of a wet sweater being laid out to block really loosens up the stitches, so I’ve started to pin out my swatches more aggressively to try to mimic that weight. I never used to pin swatches before because I don’t pin out my finished projects usually, but this has helped the last couple of sweaters I’ve knit match my swatch gauge so I know what to expect. I’m also a loose knitter and almost always have to go down a minimum of one needle size.

  14. This is something of a re-statement of Jennifer’s post but here goes nonetheless. I always try to remember that swatches – and particularly the gauge part – “lie.” I find it essential to stop and measure as I am knitting along to be sure that I am getting the gauge I need and more importantly, the size I want. It is easier to make corrections without having to rip everything out. Invariably if I fail to check often I have problems. Ask me about the sweater with sleeves that were 6 inches too long…

  15. Your previous posts on row gauge have been a HUGE revelation for me, particularly for my last jersey that I knit (shaping etc in exactly the right spots!). I always knit and wash/block a swatch for big projects like jerseys. Tend to wing it with hats etc as they’re small enough that if I do need to rip and redo, it’s not a big deal.

  16. I usually do a swatch and this week I did 4 swatches – 2 of them with a new yarn and I had to try if it was suitable for the test knit. The other two swatches are a headache now – 2 years ago I knitted with the same cotton yarn but the request was for US 6 and US7 needles. Now the test knit indicates US 2.5 and US 4 needles. I measured and it is almost the same number of stitches/rows as two years ago with larger needles. What have I done differently? Is it possible?

    • Your tension could definitely have changed from 2 years ago. It can also be a factor of wood vs metal needles, whether the yarn is dyed or undyed, what mood you’re in! The yarn could also be a little different, if it’s from a different year and lot.

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