How many times have you spotted a pattern and thought “that yarn I’ve got at home would be perfect for this,” only to find that it turned out not to be?
There’s a lot of science involved in yarn substitution and taking the time to make the right choice is important for the success of your projects.
This post will help, if, like me, you like to put your own spin on knitting and crocheting and deviate from the yarn mentioned in the pattern.
Being able to substitute one yarn for another is also important for when yarns get discontinued, but you want to re-use the pattern.
What is yarn substitution?
Designers create patterns with a certain type of yarn in mind and this will be mentioned on the pattern itself. This is because yarns can vary greatly in terms of thickness, weight, tension or fibre. Wool from different animals will behave differently when you knit or crochet with it, for example, wool from a sheep has a different drape, stretch and bounce to alpaca wool. There are also many other differences between natural yarn and acrylic and polyester blends, which are made from harmful plastics, bad for the environment and can negatively impact skin conditions, such as eczma or dermatitis. I always choose natural fibres, for my shop and for my personal yarncraft projects.
What do I need to know if I want to substitute yarn?
Certain elements are key in yarn substitution. It’s important to check the weight and yardage and also the gauge, before getting started on a project.
‘To figure out how much yarn you’ll need for your project, find out the total amount of yardage needed (it should say on your pattern) and divide this by the amount of yardage in the ball of the yarn you are wishing to use as a substitute, which will tell you how many balls you will need to substitute the original.’ (lovecrafts.com)
If the label is missing from the wool you want to use, or you are knitting or crocheting with previously used wool, then measuring the wraps per inch can help you to identify the weight of the yarn. Wrap the yarn around a pencil for a few inches, with no overlaps or gaps. Keep the wrapping with an even tension. Next, use a ruler to measure the number of wraps in an inch. You can then use this chart, from Craft Yarn Council to work out the weight and which knitting needle or crochet hook size to use.
| CYC weight | WPI |
| 0 Lace | 30-40+ |
| 1 Super Fine | 14-30 |
| 2 Fine | 12-18 |
| 3 Light | 11-15 |
| 4 Medium | 9-12 |
| 5 Bulky | 6-9 |
| 6 Super Bulky | 5-6 |
| 7 Jumbo | 1-4 |
This chart is based on WPI information shared by industry experts and the two WPI lists noted below.
http://woolery.com/yarns/help-withyarn-sizes/wraps-per-inch.html
http://www.ravelry.com/help/yarn/weights’
As wraps per inch can easily be influenced by how tightly the wrapping has been done, it’s also advisable to knit or crochet a swatch first. Although this takes time, it’s time well-spent, rather than finding out much later down the line that the yarn isn’t a good match for your pattern, or you run out of yarn before the end and find it’s been discontinued!
If this has spurred you on to use up more of the wool from your wool stash, you might also find my blog post from May helpful:
https://yarnybees.co.uk/2024/04/25/have-you-got-a-yarn-stash-how-can-you-make-the-most-of-it
If you live in or around Lichfield and you’d like more advice around choosing the right yarn for a project, why not pop into my new premises at Unit 2, 69 Upper St John Street, WS14 9DT, where I’d be happy to help.
References
‘Yarn substitution’ 27/11/2023
‘How to figure out yarn substitutions’ Love crafts, Bagwell, E. 1/8/2016
https://www.lovecrafts.com/en-gb/c/article/how-to-figure-out-yarn-substitutions
‘How to Measure Wraps Per Inch’ Craft Yarn Council
https://www.craftyarncouncil.com/standards/how-measure-wraps-inch-wpi