Several years ago, I wrote a fairly in-depth article about how to substitute yarn for your knitting projects.
However, it was far from exhaustive. And last week, I came across an interesting conversation on Ravelry where a knitter was struggling with getting proper gauge using a yarn substitution for the Just Plain Gloves pattern. The knitter was trying to get another yarn, Brown Sheep’s Lamb’s Pride Worsted (labelled as aran weight, the yarn weight I called for in the pattern if one wasn’t using Knit Picks Wool of the Andes Superwash like I did—see my note below) to fit into the same dense gauge I used to make these gloves.
In the replies, user nmpalmersue gave a very astute response regarding these two yarns, which she gave me permission to share with you.
Funny thing about yarns. There is a lot more to them than just recommended gauge. Some yarns have a wide range of gauges they can be knit at and others have only a narrow range though both yarns might fall in the same weight category. The fluffier the yarn is and if it has strands that are not tightly plied, the more likely that the yarn has a wider range of gauges. KnitPicks Wool of the Andes worsted is one of those. I have used that yarn quite a bit and though the recommended gauge is 18 to 20 sts/4 inches, I find that 18 sts/4 inches is pretty loose (at least for my taste), but 20 sts/4 inches is about right and still leaves a light drapey fabric. At 22 sts/4 inches, you get a firm fabric with body and at 24 sts/4 inches, you get a very dense fabric. If you are using another yarn brand, it might not be as fluffy as WOTA and getting to 24 sts/4 inches might be a real stretch.
One way to tell if your (wool) yarn can be knit at a tighter gauge is to do a “fluff” test. Pinch it with the thumb and forefinger of both hands spaced about 2 or 3 inches apart and stretch it. If the yarn noticeably thins out and you can move your hands a noticeable distance apart, it is a fluffier yarn and you can knit at a tighter gauge. If you can’t pull your hands apart much and there is little difference in yarn thickness, the gauge range will be smaller. If you are using another yarn instead of WOTA, that might be part of the problem with getting a tighter gauge.
Another clue as to gauge range is to look at the weight of the skein. The average worsted weight for a yarn is about 100 yards/ 50 grams. If the yardage is less, the yarn is denser and less likely to compact into smaller stitches than given by the recommended gauge. If the yardage is more, the more likely you can knit it at a tighter gauge. Single ply yarns are generally the most dense of all with less of a gauge range.
Unfortunately, there is a lot more to yarn gauge than is typically given in a pattern that has a great deal to do with how the yarn is actually constructed - woolen or worsted spun, number of plies, how the yarn is plied (such as chainette or standard ply), so substituting a yarn for the one given in a pattern might or might not be successful. The other yarn characteristics must also be taken into consideration.
Note on the yarn:
While researching this post, I found out that I may have been mistaken—I was under the impression (who knows why) that Knit Picks Wool of the Andes is an aran/heavy worsted yarn, but while I was looking for evidence to support that belief, I couldn’t find any. It is classified as worsted, though I do find it to be a heavier worsted than other “worsted” yarns I’ve worked with.
So, thanks to these two events (the struggling knitter and the realization that I was operating under false information), I have now updated these two patterns and their listings to call for a worsted weight of yarn. I have used true arans to get a gauge like these patterns called for, but it is much easier to get this gauge with worsted yarn.
By the way, another lovely yarn I recommend for both of these patterns is Knit Picks Swish Worsted. The yarn is soft enough even for my sensitive-skinned third child. This would also be a good choice for the Secret Garden Fingerless Mittens or War Bride Beret.
Happy yarn substituting!