Perhaps one of the most confusing things for new knitters (and some not-so-new knitters!) to grasp is the concept of yarn weights. Oftentimes, the problem lies in the fact that different companies and references use slightly different weight definitions or requirements. In April of 2003 the Craft Yarn Council of America (CYCA) collaborated with publishers and craft manufacturers to develop a series of guidelines for various craft disciplines. These guidelines were meant to bring more consistency to the market of needles, yarn and patterns.
Fingering weight yarn is often used for baby items, socks, and awe inspiring Fair Isle patterns. Fingering weight is sometimes listed as "baby yarn" and is about double the weight of lace yarn. It also works well if you would like to knit a lace shawl with a bit of substance.
Sport weight yarn and DK weight yarn (double knitting) are often viewed as interchangeable, but they do have a slight difference. Sport weight yarn is a teeny bit lighter or finer than DK weight. Note: the word ’sport’ is not meant in the athletic sense, but rather in the women’s sportswear sense. Use these weights for socks, accessories, shawls, wraps, and heirloom sweaters like those inspired by Norwegian ski clothing.
Worsted weight yarn is the most widely available weight of yarn and the most frequently used. You may think it would be more aptly named ‘bested’ yarn, but the moniker was actually derived from an old town in England. At double the weight of fingering yarn, worsted weight yarn is great for knitters of all skill levels and can be worked into nearly anything. Heavy worsted weight, as you may have guessed, is just a hair heavier than plain old worsted weight. Good for the same range of projects as worsted weight.
Bulky weight yarn is, again, about twice as thick as worsted weight yarn. The greatest part about bulky weight is that it can be worked up quickly on large needles. For those who want instant knitting gratification, try a project with bulky weight yarn. Use for sweaters, throws, felted items, or home decor.
Super bulky is the ultimate for making fast knits. At 2 stitches per inch, you could knit up a small project in a couple of hours; a larger project in a few days. Some yarns which are quite fuzzy are categorized as super bulky. The reason for this is that in order to showcase the fuzziness of the yarn, knitted stitches need to be far enough from one another to allow the halo to spread out.
Lace weight yarn is particularly troublesome to categorize. It isn’t the yarn weight that is difficult to identify (any yarn finer than fingering weight can qualify as lace weight), but rather the gauge. To count stitches per inch just doesn’t work when it comes to patterns containing many deliberately placed airy, holey designs. Knitters who prefer a tightly stitched lace will choose to use size 2 or 3 needles. On the other hand, those knitters aiming for a gossamer-like feeling will knit the very same pattern with size 6 or 7 needles. Lace weight yarn is very fine and is best for creating delicate, web-like items such as openwork shawls and scarves. Exact measurements aren’t necessary with many lace garments so one is free to experiment and enjoy making the type of fabric that suits one’s preference.
The Carrying weight yarn category is the result of the more decorative, or novelty, yarns that have become popular over the last few years. These yarns lack substance or structural integrity when examined alone. They are designed to go along for the ride with the more substantial yarn that you are knitting with. For instance, you might carry along an eyelash yarn with a wool yarn when knitting a scarf to give it some extra pizzazz. The wool "carries" the eyelash yarn like a fashionable purse. When adding a carrying weight yarn to a project, use the weight of the more substantial yarn to make gauge calculations.
Once you have a good understanding of how these icons relate to the information on yarn labels or in patterns, a whole new world of opportunities will open up for you in your knitting journey. To start with, you will be able to easily determine what yarns can be substituted for the suggested yarn in a pattern.
Possessing an awareness of yarn weights will permit you to consider projects that will make use of the skein fragments in your stash. With all of your odd bits of yarn sorted into their respective weight classes, you can creatively transition between different colors and textures within a sweater, for instance. Note: Use the handy Wraps Per Inch (WPI) Tool to determine the weight of those yarns in your collection that have lost their labels.
Please note that these icons and weight classifications are intended as guides, not steadfast rules. They will aid you in being as creative and comfortable with your yarns as possible. Don’t be afraid to play around with your yarn! Some of the best textures and looks are created unintentionally by "knitting outside the lines". See what happens when you knit with a super bulky on small needles. Alternately, check out the loose webbing that occurs when you knit with a finer yarn on size 15 or 17 needles. The sky is the limit!