Nearly every knitting pattern you will ever look at will give you gauge or tension information that is vital to working your project successfully. This important information tells you the gauge that the designer achieved while working the pattern. If you want your project to fit and drape in the same way that the original does, then it is essential that you match your gauge to the designer's intended gauge for the project.
But how many times have I heard people say that they never do a gauge swatch? Time after time knitters tell me that 'I always knit to gauge', and therefore they don't bother with doing those pesky gauge swatches, they just dive into their project. Well, I've got bad news for you: 'Gauge' is not some Golden Standard that all designers must attain before they can start designing projects. Every knitter is different, therefore every designer's gauge is likely to be different from every other designer's gauge. I've seen patterns where the designer expects a gauge of 3 sts/in with DK weight yarn and size US 7 needles. Ponder that one for a bit. Three stitches in an inch is what you might expect to get with a chunky or a bulky yarn, not a yarn weight that is two to three sizes finer. I used up to a size US 13 needle and still was not able to achieve that gauge, and the fabric I was getting was very loose and holey, not at all what I wanted or what was pictured in the book, although the designer answered my questioning email with the indignant assurance that those numbers were indeed correct.
There is nothing more stressful than making an entire project and finding that it doesn't fit. I had the good fortune that my first sweater, when finished, would have been a bit loose for a gorilla on steroids. Ever since then, I have been careful to always work a gauge swatch on projects where fit is going to be essential to the success of the project.
If you have stopped into Kiwi and talked about gauge swatches, you have probably been shown these two swatches - worked by two different knitters, with the same yarn, same size needles, and same number of stitches.
Gives you pause, doesn't it?
Not only will gauge vary from knitter to knitter, your gauge may even differ from day to day and time of day to time of day. Maybe you are knitting after a very tough day at work filled with stress, and you are taking it out on your knitting. Perhaps you are knitting the next morning with a nice cup of tea at your elbow and the birds singing outside after a good night's sleep. I can promise you that your knitting is probably going to be tighter at night and looser that next morning. My gauge on the same project is tighter now than it was a year ago.
Given all this, maybe now you are thinking that it is important to do your gauge swatch before starting your project. Good for you! But do you know the proper way to work a gauge swatch? Uh-huh. The patterns don't explain that, do they? I'm going to pull the gauge information from a couple of online patterns, and we will work from there.
Example 1 - GAUGE
20 sts/28 rows = 4" in stockinette stitch
Now, if you are like most knitters, your first instinct is probably to cast on 20 sts on the size US 7 needles called for in the pattern, and knit for four inches. Then you'll leave it on the needles, and measure an inch somewhere in the middle and call it a day.
If, however, you are going to spend the time to work the entire project, and the money to buy good yarn, you might want to take the time to do the gauge properly. So, if the gauge is given (as it always is) for a 4" (10 cm.) swatch, you are going to want to cast on enough sts to get 6". In this case, that would be 30 sts. Twenty stitches divided by four inches as called for in the pattern gives us an estimated five stitches per inch. Six inches times five stitches per inch equals thirty stitches. Why do I want you to work a swatch that is 6" wide? Because you will probably have stitches that are either looser or tighter at the edges (beginning of the row) than they are in the middle when you start to relax into the row. So you want to be able to measure 4" in the very center of the swatch. Some people like to work their swatches with a garter stitch border, I don't because I feel that it throws your gauge off of true. I want the raw gauge.
Now, using a needle one size smaller than the pattern calls for, work the swatch in stockinette stitch for about 4 inches. Work one row in reverse stockinette, and then switch to a size larger needle - the one called for in the pattern - and work a further 4 inches. Work another row in reverse stockinette, and switch to a needle that is one size larger than the one called for in the pattern, and work for another 4 inches. In photography we call this 'bracketing', better known as covering your bottom. You want to work your swatch in these three different needles because if you are not able to magically hit the correct gauge with the needle called for in the pattern, you are covered for one needle size in either direction, and that usually covers all your needs. If by chance it doesn't, then you have a pretty good idea how far up or down you need to go in needle size in order to hit gauge. Too many stitches per inch? Your needle is too small, go larger and swatch again. Too few stitches per inch? Your needle is too large, and you need to go smaller. After completing your swatch, bind off, and get ready for the next stage, blocking.
Why block your swatch? Because at some point your are going to block/wash your sweater, and gauge can change a LOT after blocking. I've seen sweaters gain as much as a couple of inches in width after blocking. And you would be astounded by how much cotton can grow in length after blocking. Start by measuring gauge on the swatch before blocking. These numbers are important, write them down and save them somewhere, you are going to need them later. Take a ruler, and in the center of each area of the swatch, line the left edge of the ruler up with the edge of a column of stitches. Count the number of stitches over 4 inches, and write it down. Measure the number of rows over four inches by lining the long edge of your ruler along the side of a column of stitches, count the number or rows in your swatch, and write it down. I'm a lot more concerned with hitting stitch gauge than I am with hitting row gauge. If I can only have one or the other, I want to hit stitch gauge.
Now, grab the ball band for your yarn, and look at the washing instructions. That is what you are going to do to your swatch, either hand-wash or machine wash as required by the ball band info. If you are hand-washing, lay the swatch out smoothly on a doubled towel after washing and let it dry thoroughly before moving on. Once it is very dry (I like to leave mine over-night), measure all your gauge measurements for each section again. You might be surprised to see how much the gauge changes with blocking. Write all these measurements down next to the ones you took before blocking your swatch. Find the after-blocking gauge that matched the gauge called for in the pattern, and you are ready to start your project. Take time to measure your gauge on the project again from time to time as you work, matching it to the before-blocking gauge for the needle size you need to use to get gauge. If you can match that as you go along then you know it should match your after-blocking gauge once the project is finished and blocked.
Example 2 - GAUGE
28 sts/ 44 rows = 4 inches in lace pattern after blocking
This one takes just a bit more thinking as you have to work your gauge swatch as above, except in the lace pattern used in the pattern.
Now, the above instructions work great if you are working on a piece that is going to be knitted flat. But suppose your sweater is going to be knitted in the round, like a Fair Isle cardigan or pullover? Enter the ITR (in the round) gauge swatch...
Work the swatch with the info as given in the pattern and as above, except for this... You are going to work your swatch in the round. Why? Because very, very few knitters will get the same gauge on a stitch pattern knitted flat as they will get while knitting in the round. Most knitters have a slightly larger purl stitch than knit stitch, caused by the way that most of us wrap our purl stitches - they go the long way around the needle. This is why you get that gap after a cable, or your last knit stitch in a rib is big and funky. This can really throw off your gauge for a project knitted ITR if you don't do a proper gauge swatch, since knitting stockinette in the round is all rows of knit stitches, with no purls.
To knit a swatch for a project that will be knitted in the round, pull out two dpns (double-pointed needles) each in three sizes: one set a size smaller than called for in the pattern, one set the same size as called for, and one set in a size larger than is called for in the pattern. Cast on the appropriate number of stitches onto one needle, and knit one row. Slide the stitches all the way to the right on your needle, just as you do when working I-cord, leave a big loop of yarn in the back that will stretch across the back of your swatch without pulling it out of shape, and knit across the row again. Repeat.
Front of a gauge swatch for knitting ITR
Back of a gauge swatch for knitting ITR
Swatches can give you other useful information, too. I work them when designing patterns so that I know that the design I am working on is going to have a stitch pattern that I like, as well as to find the gauge that I am working in.
This swatch tells me that with the strand of linen I am adding to the fabric, it isn't going to have enough bounce or elasticity to correct the looser purls on my ribbing. So I work my last purl stitch of each part of the 5x5 ribbing by wrapping the stitch in the 'wrong' direction and knit it tbl on the next row, and find that corrects the ribbing for me by the time I get to the top of my swatch.
This swatch tells me that if I change the Fair Isle pattern in this sweater, then I am going to get a much tighter gauge than is called for in the pattern. But I like the weight and drape of the fabric, so I would rather reconfigure the pattern to suit my swatch, rather than change my gauge to suit the pattern.
This morning I started cleaning out my yarn cabinet and came across bags of swatches I have done for previous projects. It was fun to look at each one and remember the project it went with. Sometimes I ended up needing the yarn from my swatch in order to finish my project, sometimes I didn't. But each of those little squares of knitting equals a project that turned out the way I wanted it to, all because of taking the time to knit a gauge swatch first.