One question we get asked a lot, is about how to substitute one yarn for another in a pattern. This may be because the pattern is for a discontinued yarn but it could also because you find your perfect shade in a completely different yarn or you might have some balls you want to use up.
If you check the website of the yarn company which produced the original yarn, you may find other yarns listed that will work with your pattern. But if that doesn’t help, there are a few things you need to consider before trying to use a substitute yarn.
It is always best to try to find a yarn with a similar fibre content. If the pattern calls for wool and you want to use cotton, the drape and handle will be very different, and you might be disappointed. However, if it stipulates wool and you have a wool-effect acrylic yarn in your stash it will probably work out fine.
It is so important to check that you can achieve the same tension with your chosen yarn. Using the needle size and tension given in the pattern, knit or crochet a square and see if you can match it. If the square is far too big, your yarn might be too thick; way too small and your yarn is too thin. If your tension square is just a little out, you can adjust this by changing the size of your needle or hook.
You will need to work out how much of your chosen yarn you are going to need. The original pattern will give you the number of balls the design requires in your size. It may also tell you how many yarns or meters there are in the ball or hank. If not, you can usually find this information on Ravelry or the yarn company website.
Now you need to calculate the total length of yarn needed. Let’s imagine our pattern takes 8 balls, each with 120 metres.
8 multiplied by 120 = 960 metres in total.
Now let’s say your yarn has only 100 metres in each ball.
960 metres divided by 100 = 9.6 balls so you will need 10 balls .
If you are worried you might run out, it’s probably worth adding an extra ball, just in case.