Many a knitter has found himself or herself needing to substitute yarn for a project. Perhaps the yarn recommended for a pattern has been discontinued. Maybe the yarn is just way out of your personal yarn budget money. Perhaps the recipient for the intended knitted piece is allergic to the fiber content of the recommended yarn. It is almost always possible to find a good substitute yarn; you just need to keep these six factors in mind.
Factor 1: Recommended needle size and gauge- Check the ball band of the yarns you are considering for substitution. If the recommended needle size and gauge match up, the actual size of the item should come out about the same. If you are unsure if the gauge and needle size match up because the pattern and the ball band describe the needle size and gauge in two different ways, check the chart link for the standard yarn weight system from the Craft Yarn Council of America. This chart should help you figure out if the two yarns are similar enough in gauge and recommended needle size to get a good match.
Factor 2: Fiber type- Gauge and sizing alone isnít enough to get a good yarn substitute. Silk and bamboo yarn have specific drape that cotton does not have, so if you try to substitute cotton for a silk/bamboo blend, you will not get the intended effect in your knitting. Directly going from one fiber type to the same fiber type, such as wool for wool, will produce the most similar result.
If this isnít possible, then here are some tips: wool can be substituted and given a similar effect with cotton or acrylic yarn. If you are knitting cables and cannot use wool, acrylic will give better stitch definition than cotton. If a pattern suggests cotton, wool does not substitute as easily. Try using different cotton or a cotton blend. Silk, bamboo and viscose yarns may be substituted by some specialty synthetic ribbon yarns. When substituting silk, bamboo or another viscose, try to stay within that group just listed.
Factor 3: Ply single, double or more?- The ply of the yarn will strongly affect how the yarn behaves in your knitted garment. I once knitted a sweater from a bulky weight wool single ply, and the knit stitches almost seemed to form a slanted line, as the stitches all slanted with the twist of the ply. It was nice in the sweater, but taught me a lesson about how plying of the yarn affects the finished knitted piece. A double ply will be twisted in opposite directions, encouraging the yarn to behave in a straighter fashion.
Factor 4: Amount of yarn per skein- If your pattern calls for five balls of X yarn, and X yarn has 300 yards each, than buying five balls of Y yarn and 150 yards each will leave you seriously short of needed yarn! Most knitters know that you should buy all of your yarn at one time for a project in order to get the same dye lot. Do the math to make sure that the needed yardage or meters will be the same. Simply multiply the number of yards/meters in the recommended yarn times the number of balls required, and then make divide that number by the yards/meters in each ball of your possible substitute yarn. This will tell you how many balls of the substitute you will need.
Factor 5: Yarn Texture- Is the yarn in the pattern a chenille, a boucle, smooth, eyelash or wispy? Substitute a different texture in, and you will get a big surprise that you my not like! That smooth yarn needed for your cabled sweater project shouldnít be substituted by an eyelash yarn that will hide all of your stitch work. Likewise, a sweater knit in soft chenille or cuddly boucle may look and feel dull when knit in a perfectly smooth, yet more inexpensive yarn.
Factor 6: Color and Dye Type- The dye process and coloring of the recommended yarn will also give an indication of what you should be looking for in a substitute. Cabled or lacy knitting doesnít always show its nice stitch work in dark colors that obscure the stitch patterns. A light heather or tweed may enhance a cabled project, but patterned printed yarn or dyed ombre will look busy and overwhelm the stitch pattern.
After considering all of the factors, and making a choice of which yarn you plan to substitute with, be sure to knit a swatch. Swatches can tell you so much more then just what gauge you will get. That little swatch can also tell you how the substitute yarn will really look knitted in the stitch pattern and style, and how the knitted fabric itself will behave. You can also try blocking the swatch to get some ideas on how blocking may be affected by your substitution choice.
Offsite link: Standard Yarn Sheet