...a field guide to yarn substitutions

If a pattern specifies a particular yarn, then that's the yarn you have to use, right?

Of course not.

There are several reasons why you might choose to use a different yarn. Perhaps the specified yarn is now discontinued. Maybe the cost of the specified yarn is beyond your means, or in a fit of financial restraint, you've decided to dive into your stash for a replacement yarn.

Some knitters don't think twice about swapping out the pattern's choice of yarn for their own. But others get downright nervous at the thought of deviating from the written word. For those of you who might fall into this second group, this article is for you. As you'll read below, making a judicious substitute yarn selection is simply a matter of asking yourself three basic questions.

Question One: Does my yarn knit to the gauge required by the pattern?

First, you need to make sure that you can knit your potential substitute yarn to the gauge specified in the pattern.

If your pattern provides gauge information for stockinette stitch, it's easy to figure out whether your alternative will knit to the same gauge by comparing the pattern's target gauge with your yarn's label gauge. Ideally, you'd confirm the match by knitting and blocking [or laundering] a gauge swatch.

Labels aren't laws. This alpaca/wool yarn has a "label gauge" of 4.5 stitches per inch - typical aran weight. But on 2.75 mm needles, it knits to 7 stitches per inch and still maintains a soft hand.

When the design incorporates lace, textural stitches, or colorwork, the pattern instructions may direct you to knit a gauge swatch in something other than one-color stockinette, which will affect the final gauge of the knitted fabric. In that case, the best way to verify that your yarn will work is to knit that swatch. Sometimes, it's just not feasible to knit a gauge swatch before purchasing a substitute yarn. In that case, you'll have to rely on a comparison of the stockinette stitch gauge of the pattern's specified yarn with the stockinette stitch gauge of your intended replacement. Although it's not a guarantee, it's often a good indicator of whether your yarn will knit to the pattern gauge.

So, when you begin your search for the perfect substitution, you'll probably start in your local shop or online, looking at the yarns that are labelled with a gauge that matches the pattern's specified yarn. But don't forget, potential substitutes might also be found in other gauge [weight] categories. By increasing and decreasing your needle size, you can alter the gauge and characteristics of the knitted fabric.

Radical changes to the knitted gauge of your yarn will likely affect the behaviour of the knitted fabric. And this leads us to the next question:

Question Two: Will my yarn behave the way the pattern expects it to behave? [And if not, is that okay?]

Next, take a little time to study the pattern design.

Examine the drape of the garment on the model [if available] to determine how the knitted fabric should behave. Should it drape softly? Should it have more body? Do you like the way it looks? If you use your alternative yarn, will your knitted fabric do that?

For example, Topsecret from Knitty's inaugural issue specifies a gauge of 12 stitches over 4 inches. The two yarns pictured below knit to the same gauge, but only one of them would be a suitable alternative to the original yarn. The wide sleeves and cowl of Topsecret benefit from a fabric with more flexibility and drape, which is provided by the pattern's specified yarn. The bulky cotton bouclé shown below would provide this needed drape.

Same gauge, different results. Belle Vallée 4-ply rug wool [top], and Adrienne Vittadini Adriana cotton boucle [bottom] knit to the same number of stitches and rows per inch, but they behave differently. The thick wool fabric is stiff there's little space between the stitches, so the fabric is less flexible. The cotton bouclé is bulky too, but the space between the stitches [obscured by the texture of the yarn] gives the fabric more drape.

Also examine the stitches and techniques used in the pattern. Are there twists and cables? They may be more difficult to work in an inherently inelastic yarn, such as cotton or linen. Is there knit and purl-textured patterning? It might be hidden by a furry or fuzzy yarn.

Sometimes, the designer may have specifically designed a garment to highlight the features of the specified yarn. The construction of Rosedale and Tilt, for example, turn the long color gradations in Noro yarns to advantage. In a yarn without those slow, progressive color shifts, the clever engineering of these garments is less apparent.

If you already knit a gauge swatch in pattern, you probably noticed any shortcomings in your substitute yarn choice. If you haven't swatched, keep these considerations in mind when selecting your replacement yarn.

Question Three: How much yarn will I need?

Now, it's time to engage in some simple arithmetic.

Once you've identified a suitable alternative yarn, you just need to make sure you've got the same length - not weight - of yarn indicated in the pattern requirements. Length is a more accurate measure than weight because different yarns have different densities. A cotton and a wool yarn may knit to the same gauge, but you'd find that a ball of the cotton yarn will have less yardage than a similarly sized ball of wool.

From the pattern's yarn requirements, multiply the number of skeins, balls, or spools with the yardage of a single unit. For example, if the pattern calls for 13 skeins of yarn with a yardage of 121 yards, then you'll need a total of 13 x 121 = 1573 yards in your substitute yarn. Make similar calculations with your substitute yarn to make sure that you have enough.

Sometimes patterns omit the yardage information. In that case, you'll have to look up the yarn's vital statistics using one of the suggested resources below.

Substitutions, in summary

To précis the search strategy discussed in this article, it boils down to three simple steps:

Follow these steps, and you'll be making confident yarn substitution decisions.

Resources

Online searching for gauge and yardage information of current yarns: try an Internet search engine such as Google, or visit an online yarn shop and browse through their selection.

More information on gauge and weight categories: consult the Craft Yarn Council of America's new standards table [not all publishers or vendors follow this table, but it provides useful guidance].

Online information about discontinued and/or "vintage" yarns:
wiseNeedle is a free database of current and discontinued knitting yarns, including yardage and gauge information and user-submitted reviews.

Vintage Knits has tables listing the yardage and fiber content of discontinued yarns, categorized by gauge.

Offline information about current and discontinued yarns:
Valuable Yarn Information is a cerlox-bound book with yardage and gauge information for 13,000+ yarns, updated twice yearly and available for sale from knitting shops.

Knit Wise®Yarn Finder covers 3,000 yarns and is available on CD-ROM or in print.

Long out of print, Maggie Righetti's Universal Yarn Finder [Prentice Hall, 1987] provides information about fiber composition, gauge and yardage of older yarns.