(edit to add: If you are more of a visual learner I have made a video where I discuss this subject in a little more depth than this post. Check it out by clicking on this link to YouTube.)
In my last post I mentioned that I am trying to create a different look for the Scarab Shawl by making a new version in a different yarn. Which brings to mind an issue near and dear to many knitters hearts; knitting a pattern in a yarn other than the one called for by the designer.
Tons of fun for some people, an enigma wrapped in a riddle for others. So I am gonna try and shed a little light on the subject for those who find themselves wandering around their LYS scratching their heads while clutching a skein of yarn to their chest.
First off – not all yarn in a given stated weight is precisely what it says it is. Think of the different yarn weights as more of a range of sizes as opposed to a single size of yarn. You can have light fingering, standard fingering and heavy fingering all labeled fingering. That being said, yarn typically comes in the following weights (in increasing order of size):
- Fingering (or Knitting weight in the UK/Europe)
- Sport (not particularly available outside of North/South America)
- DK (which stands for Double Knitting)
- Worsted (not particularly available outside of North/South America)
- Aran (double the weight of DK)
On a basic level, if you are looking at the UK designations there is actually a logical progression of weights. If you double Lace-weight you get Knitting-weight. If you double Knitting-weight you get DK. Double DK = Aran, it is all logical kinda like the metric system.
Both Sport weight & worsted weights were US inventions for yarns to fall into the ‘in between’ spots. Double Sport weight and you get Worsted, and if you double Worsted you get Chunky/Bulky! There are very fine lines between the weights of these yarns, which is why I prefer to look at the yardage vs weight to decide if something is going to substitute.
Take Madeline Tosh DK, I am working on a pattern in it right now and it is a beautiful yarn.
It says DK right in the name right? Well, if you were wanting to substitute yarn in a pattern designed for this yarn it might help you more to look at the yardage vs weight. In a 100g skein of this yarn you get 225 yards. Doing a quick search in the Ravelry yarn database and selecting >DK>Wool I see that Rowan has a lovely DK weight wool called Pure Wool which might work out for me. But lets look deeper.
Pure wool comes in 50 g skeins with 136 yards per skein. Multiplying this out to match the 100 g of Madeline Tosh you get 272 yards per 100 grams. Hmmmm? When you take the same weight of the same fiber (wool here) and stretch it out to have more yardage you will end up with skinnier yarn. Comparing 225 y/100 g to 272 y/100 g, the Rowan is going to be much thinner yarn.
In contrast, lets look at the stats for a very popular ‘Worsted’ weight yarn. Cascade 220 tells you right there in the name that it has 220 yards in its 100 g skein. At the very lightest end of what can be considered worsted weight, Cascade 220 would be a better substitution choice for Madeline Tosh DK than the Rowan DK.
You might notice that I stuck to comparing wool to wool. That is because other fibers weigh in differently and open up another can of worms. Fiber content changes not only the weight of the skein, but also changes the way the yarn behaves. Some fibers are much more “drapey” than others, which can or can not be desirable depending on the pattern. A short and non-comprehensive list of fibers that can make your yarn more “drapey” would include: alpaca, silk, tencel, and bamboo.
Another thing that can significantly effect how a yarn knits up is the structure of the yarn itself. Single ply vs plied yarns and the different kinds of plied yarns all knit up differently. Sticking to something that is similar in content and construction to the originally called for yarn can help you be more successful in substituting yarn. edited to add: If you are interested in a deeper discussion on these different elements that effect yarn substitution check out this video on the subject.