You may want to substitute yarn because:
- The suggested yarn is not available.
- The suggested yarn would exceed your project budget.
- You want to knit/crochet from stash.
- You or the recipient are sensitive to certain fibers.
- Care requirements for the suggested yarn are unrealistic for you.
This summary assumes you want your item to look as much like the pattern photo as possible. That is not always the goal, of course.
First, consider yarn weight.
Simple Answer: Choose a yarn that’s the same weight category (fingering, sport, DK, etc.) as the pattern suggests. This will probably work out OK if you swatch. (Always wash your swatch and let it dry in whatever way you will launder your final object, to see how the yarn will behave under real world conditions.)
Detailed Answer: Look at the yards or meters per gram and each yarn company’s estimated stitch gauge. Find this information on the yarn label or on Google.
Example
Pattern suggests “Pattern Yarn” fingering.
Google says Pattern Yarn fingering is 440 yards per 113 gram skein.
Yards per gram = 440 divided by 113, or 3.89 yards per gram.
You want to use “Stash Yarn” fingering.
Label says it’s 425 yards per 100 grams.
Yards per gram is 425 divided by 100, or 4.25 yards per gram.
Now you know that Pattern Yarn is probably a bit thicker than Stash Yarn. Is it close enough? Let’s look at gauge.
Google says Pattern Yarn fingering is 7-8 stitches per inch on size 1-2 needles or B-C hooks.
Label says Stash Yarn is also 7-8 stitches per inch on size 1-3 needles or B-E hooks. Note that the tool size range to get gauge is slightly larger.
Now you know that Stash Yarn will probably work, but you might have to use a slightly larger hook or needle to make gauge. This means your stitches could be looser. Look at the photos in the pattern and decide whether the item will look OK with slightly looser stitches. If it wouldn’t, it’s time to pull something else from stash and try the comparisons again.
Next, consider the spin.
Common spinning styles are worsted spun, woollen spun, single-ply and chainette. Check the labels, or Google the yarns to determine the ply of the pattern yarn and your preferred yarn, if you aren’t sure.
Simple Answer: Yarns spun differently act differently. If you want to match the photo, match the ply.
Detailed Answer: The way yarn is spun and the number of plies it has harness the kinetic energy of the fibers in a particular way. For example, worsted spun yarn fibers press inward; woollen spun yarn fibers press outward. Don’t want to match the spin? Swatch the texture or technique of the pattern and see if you are satisfied with how it looks. Pro tip from YarnSub.com: If your pattern uses ribbing, swatch bit of that, too.
- Appearance. Worsted spun yarn looks the most uniform. Woollen spun and single-ply can look a bit more rustic. Chainette varies quite a bit depending on the exact weave and the fiber used but in general has fairly even stitch definition.
- Knit swatch examples: ModernDailyKnitting.com
- Crochet swatch examples: LindaDeanCrochet.com
- Wear and care. The number of plies in a yarn affects how the item will wear and how it must be cared for. In general, the more plies a yarn has, the sturdier it is, so worsted spun 8-ply wears better under abrasion than single-ply, for example. The spin and the fiber together dictate care. Consult the label or Google for care information.
- Type of item. Consider the type of item you’re making when determining whether a difference in spin matters. Some items, like shawls, are subject to less abrasion and are laundered infrequently. Others like socks experience a lot of abrasion and are laundered frequently.
- Weight. Worsted spun yarn is more dense, so larger items will be heavier than items made with woollen spun or chainette yarns. This weight may change the appearance of the item.
Now consider fiber content.
Simple Answer: Different fibers behave differently. Match the fiber content as closely as possible, using the label or Google. There is some wiggle room with blends of wool, cotton or linen that can affect the care, breathability and wear of your garment but not alter the appearance too much.
Detailed Answer: Match the characteristics of the fiber rather than the fiber itself. The Fleece and Fiber Sourcebook is an excellent reference.
- Drape. Look at the photos in the pattern to see how fluid or structured the fabric is (the “drape”). In general, fibers that drape more include silk, tencel, alpaca, linen, bamboo and any other slippery, shiny yarns such as superwash wool. Fibers that create more-structured garments include non-superwash wool, acrylic and unmercerized cotton.
- Memory characteristics. How will the fiber behave over time? For example, pure silk and alpaca can lose shape and not bounce back in larger pieces.
- Weight. For example, larger pieces can be quite heavy in cotton and can grow even larger over time.
That’s it!
Comparing the yarns’ weight, ply and fiber are the essentials of yarn substitution. Some additional topics follow that may be of interest.
Substituting plant-based fibers for animal fibers
Simple Answer: YarnSub.com will let you specify non-animal fibers in your search. Even if the listed yarn isn’t available in your area, it will tell you the sort of yarn that will work.
Detailed Answer: In general, swapping plant-based fibers for animal fibers is a bit more art than science and can require experimentation.
- WorldOfVegan.com has a quick chart that lists the characteristics of various non-animal yarns as well as lots of other tips.
- Knitty Magazine editor Amy Singer’s “No Sheep for You” book explores the characteristics of various non-animal fibers in detail to give you more insight into using plant fibers in patterns for animal fibers.
Breed-specific wool
Simple Answer: Sheep’s wool comes in variations of crimp, fiber length and fiber diameter that all affect the way it knits/crochets. To get the same effect as the suggested yarn, use yarn from the same breed of sheep.
Detailed Answer: Breeds of sheep are roughly divided into categories based on staple length, crimp and fiber diameter. Substituting within these groups will provide more accurate results. There’s some overlap but in general, the categories are:
- Finewool. Merino, Rambouillet, Cormo, Targhee.
- Medium and Down. Dorset Down, Dorset Horn, Shropshire, Suffolk, Hampshire, Welsh Mountain, Clun Forest, Southdown, Oxford, Cheviot, Finn, Columbia, Tunis, Shetland.
- Hill/Mountain. Scottish Blackface, Herdwick, Swaledale.
- Longwool. Romney, Lincoln, Leicester, Cotswold, Coopworth, Border Leicester, BFL, Wensleydale, Perendale.
- Double-Coated. Icelandic, Karakul, Navajo Churro.
For more about breed-specific wool, including which categories are best for next to the skin, etc., visit Making-Stories.com and SolitudeWool.com.
Identifying mystery stash yarn
If you don’t remember what the yarn is and the label is missing, you can still determine yarn weight and general fiber content.
- Weight. To determine the weight, weigh two yards/meters on a kitchen scale in grams, and divide by 2. Compare the result to the yards or meters per gram number of the pattern recommended yarn (see the yarn weight section). You can also use wraps per inch (WPI) to determine yarn weight. Wrap your mystery yarn around a ruler or WPI gauge, then count how many rounds make an inch. See CraftyYarnCouncil.com for more information.
- Fiber Content. For a general idea of the fiber, you can carefully burn a bit of the fiber and see how it reacts. Be sure to take all precautions. Handmade by Stefanie has a tutorial.