Yarn substitution is a quirky quandry. As we all know, there are six different yarn weights:
|Yarn Weight||1: Super Fine||2: Fine||3: Light||4: Medium||5: Bulky||6: Super Bulky|
|Yarns in Category||Baby, Fingering, Sock||Baby, Sport||DK, Light, Worsted||Afghan, Aran, Worsted||Chunky, Craft, Rug||Bulky, Roving|
|Needle Size (US)||1-3||3-5||5-7||7-9||9-11||11 and up|
|Average stitches per 4 inches||27-32||23-26||21-24||16-20||12-15||6-11|
The problem is that not all worsteds, for example, are alike. Nor are any other yarn weights consistent across all manufacturers and brands of yarn. So the first lesson is knowing that just because a skein wrapper says worsted doesn't mean it is interchangable with every other worsted.
This issue really played out looking for substitution yarns for the Barton. Most knitters couldn't afford the $400 to $600 price tag for the Bijou Basin Bliss, a yak/cormo wool blend sport weight used to make the sample garment. Marly Bird, the designer, emphasized that knitters should avoid plant-based yarns (cotton, linen, silk, etc.) and instead use animal-based fibers like wool. She also warned against using softer animal fibers such as merino and alpaca because they wouldn't hold the sweater's shape well.
The search ensued for a suitable alternative sport weight. I compared the yardage per gram between several sport weight yarns. The specified Bijou Basin Bliss weighs in as follows: 150 yards per 56-gram skein. So, the average yardage per skein is 150 yards divided by 56 grams equals 2.67 yards per gram.
Then we looked at sport weight yarns, all of which are 100% wool.
|Classic Elite Portland Tweed||Knit Picks WOTA Sport||Reynolds Whiskey||St. Denis Nordique||Cascade 220 Sport||Bijou Basin Bliss|
|Skein in grams||50||50||50||50||50||56|
|Average Yardage per Skein||2.4||2.74||3.9||3.0||3.28||2.67|
Optimally, you'd want a yarn that's very close to the 2.67 average yardage per gram of the Bijou Basic Bliss. This would ensure that you're knitting your sweater in the same weight as the one shown in the pattern. Here's the start of my swatch using the prescribed yarn.
Now look at the Reynolds Whiskey. It's 46% lighter than the Bliss, so I'd worry that this yarn wouldn't work, but I've seen a beauteous swatch created by Pam. She was able to make gauge with the Whiskey - and that's the most important goal. If you can get gauge and you like the resulting fabric, you're golden. This yarn will result in a lighter, less dense cardigan than the original.
On the heftier side is Classic Elite Portland Tweed, which is 11% heavier than the Bijou Basin Bliss. This yarn will yield a bulkier version of the cardigan. This pretty swatch was knitted by Liz.
Now let's look at the Banstead, which is knitted in Blue Sky Alpaca Suri Merino, a soft, haloed, worted alpaca/merino blend. Lyn, who is allergic to animal fiber, wanted to knit the Banstead with Berroco Mica, a slippery, shiny linen/cotton/silk/nylon DK weight yarn. Let's compare the average yardage per gram. The Alpaca Suri Merino weighs in at 1.64 yards per gram; the Mica gives 2.7 yards per gram - a 35% lighter yarn. But the fibers are different weights, right? Lyn swatched - and hated the result so she's off to the LYS today to find something else.
So what are the questions you should ask when you swatch with a replacement yarn?
- To make gauge, will the garment lose it's shape if it's knitted loosely? (Cotton sweaters routinely lose their shape.)
- Will there be big gaps between the stitches so you can see her undergarments underneath?
- Do you like the way fabric and the way it would hang on the body?
To learn more about yarn substitution, check out these resources:
Knitty's A Field Guide to Yarn Substitutions
Knitting Daily Gauge and Yarn Substitution
A Guide to Yarn Substitution