A necessary part of becoming a proficient knitter is learning how to substitute yarns. Changing the yarn in a pattern for a different yarn can be necessary for a number of reasons, such as the yarn being discontinued, being made from a fiber you don't like or are sensitive to, being out of your price range, or simply being unavailable for another reason.
It is not that difficult to substitute yarns, but the prospect of finding the right yarn to complete a project can be quite daunting for beginning knitters. Here are some tips on how to choose the right substitute for a yarn given in a pattern.
Before you go to the yarn store or your favorite online shop to look for a yarn to replace the one used in a pattern, you need a little bit of information about the yarn that was used in the pattern.
The most important piece of information you need about the yarn in question is its gauge or the number of stitches and rows per inch that the designer got when she or he worked the pattern.
So for instance in a fingerless gloves pattern knit with Rowan Big Wool, the gauge is two and a half stitches and three rows per inch knit in the round on size 15 circular needles.
That tells you that if you want your finished project to be the same size as the project in the pattern, you will need to find a yarn that allows you to knit that same gauge. Virtually every pattern you will ever come across will tell you what the gauge was, even if it says the gauge isn't important to the finished piece.
If a pattern doesn't tell you the gauge, it likely will tell you the weight of the yarn, whether its chunky, worsted or fingering weight. Some patterns that give gauge will also tell you the weight of the yarn, which is handy information to help in your search.
Knowing the weight of the yarn can help you narrow down your search in the yarn store. You can ask to see only super-bulky yarns in the yarn shop if that is what you need, or most online shops have an option to search by weight. This will save you a lot of time by eliminating the yarns that simply won't work for you.
Finding the Right Fiber
Now that you know the gauge and weight of the yarn that was used in the pattern, you can begin to look for a yarn with a similar gauge to use for your project.
How do you know if a yarn has a similar gauge without knitting it? Most yarn bands will give you an estimate of how many stitches and rows the yarn works up to on a certain size needle over an inch or four inches. This is often presented graphically with a number of rows and stitches shown on a grid with a particular needle size named outside the grid.
Whether the gauge information is listed in words or as a picture, it's pretty unlikely that you'll find a yarn that perfectly matches the gauge that was given for the project you are looking at. That's because different companies use different sized needles to make their gauge swatches, and you might not find a yarn that indicates the same size needle your pattern calls for.
Even if you did, the gauge probably won't be exactly the same, and even if it were, that's no guarantee that when you make your gauge swatch you'll get exactly the same gauge.
Let's go back to the wristwarmer example. We're looking for a yarn that will get us 2.5 stitches to the inch (the stitch size is much more important than the row size since you can always knit more or fewer rows to make the project fit). I like to check Yarndex, where you can search by weight and fiber, or you can just search online for things like "super bulky wool yarn" and see what develops.
Doing this I found Cascade Magnum, which knits up to 1.5 to 2 stitches per inch on size 15 to 17 US needles. With a little fiddling, you could probably get the right gauge for this project.
Picking the perfect substitute yarn has a lot to do with your personal taste as well as the dynamics of the pattern. Don't pick a yarn just because it fits the math. If you don't love it, keep looking.
How Much to Buy
Once you've found that perfect yarn that fits the gauge requirements and your needs, the next big question is how much yarn you need. Go back to the original pattern and you will likely find a measure of yardage, weight or the number of skeins or hanks used to complete the project.
If you know how many yards were used in the original project, you can easily do the math to figure out how much of the new yarn you need based on how much yardage is in each ball.
If you only have a weight or a number of skeins, you'll want to do a little more research. Search for the yarn online. If it is still manufactured, it should be pretty easy to find out how many yards are in a skein (and how much each weighs, if that is the only measurement your pattern gives) and how much yardage was used for the project. Then just divide the number of yards in your new yarn's skeins into the amount you need to determine how many skeins you need to buy.
If, for instance, the pattern used 1,500 yards of the old yarn and your new yarn has 350 yards in a ball, you'll need five balls to complete the project (the math is not usually that clean). Always round up if you don't get an even number and buy an extra skein just to be safe if the cost isn't prohibitive.
If the yarn used in the pattern is no longer made, check out the wonderful resource at Vintage Knits listing the weights, yardage, and fiber content of tons of old yarns, arranged by weight. This should help you work the math for your new yarn.
Testing Your New Yarn
Before you start working on your project with your nice new yarn, take the time to make a gauge swatch. It seems like a lot of trouble, but just because the yarn band says a yarn will work to a certain number of stitches doesn't mean it will when you are holding the needles.
Every knitter is different, and even small variations in the number of stitches per inch can make a big difference in the sizing of a knitted article. Knitting a gauge swatch is certainly not a waste when you learn that you need to use a different sized needle to get the desired result. It's much better than knitting your whole project and then finding it doesn't fit.
There is a bit of homework involved in substituting yarns for your projects, but it is not really that difficult and it allows you to make any project your own. Don't be afraid to branch out and explore the different yarns that are out there.