Yarn comes in different
weights, or thicknesses. Weight to yarn is as gauge to wire; it gives a rough approximation of the circumference of the yarn. Applying a weight to a yarn is called
yarn sizing.
Yarn sizing is about as accurate of a science as women's clothing sizing. Theoretically, it's the same basic concept: no industry-wide standard means that a size 2 dress in one brand is a size 6 in another. Early in my knitting years (pardon me while I get misty-eyed with nostalgia...), I blindly went by the manufacturer's given weight. This resulted in some unfortunate pattern/yarn pairings. It takes a practiced eye to determine a yarn's weight more accurately than the one given by the manufacturer. In fact, I've taken some liberties with my yarn
stash, or supply, and have shown the following yarns as they
ought to be classified, rather than how the manufacturer suggests.
What's the point, you ask? Why would someone need different sizes of yarn?
It's all about the application. For a gossamer-thin shawl, thread- or lace-weight yarns are often called for. A thin yarn will feature knitted lace patterns, whereas they would mostly disappear in a thick yarn. Likewise, a sweater made out of a thread-weight yarn for someone who lives in a cold environment wouldn't be the best pairing; the sweater would be super skimpy, and, most likely, not at all warming.
Yarnies -- as I like to call fiber crafters -- are a colorful bunch, and have invoked several different names for the same weight of yarn.
+ Thread can also be called 'cobweb'
+ Sock can be called 'fingering' (yes, you're reading that right) or 'light fingering'
+ DK stands for 'double knitting'
+ Aran may be referred to as 'heavy worsted'
There are also several weights of yarn that I didn't include above, simply because I don't have any on hand: bulky, super bulky, and novelty. Novelty yarns are things like ribbon, eyelash yarn, etc.
Here are several of my knitted projects, and their corresponding yarn weights. This ought to give you a good idea of how the weights look as fabric.
Every knitting pattern has a recommended yarn weight, so it's often the first thing that knitters look for when trying to find what yarn they'd most like to use. Weight is just the tip of the iceberg when it comes to describing yarn: enter ball-bands, and remove thy mind from the gutter.
Ball-bands are kind of like an ID card for yarn. They come in all sorts of forms, but contain the same pertinent information -- not included below is that they all list the yarn's country of origin, too.
The dye lot: yarn is typically dyed in bulk, and dye lots refer to the batches of yarn that are dyed together. For example: this yarn is turquoise, which the company calls #24. It's from dye lot 10116. Towards the end of my project, I run out of yarn, and need to make an emergency trip to my LYS (local yarn store). The LYS only has #24 from dye lot 12000; so, while it may be the same shade of turquoise, there may be small variations. Here's an example from a sweater I knit where I didn't match dye lots; for shame! Knitters, scroll quickly, because this is pretty ugly.
If you look on the yellow square on the chart above, you'll see 'recommended needle size' and 'gauge.' In (mostly) English, this means that the manufacturer says that, if I were to use a knitting needle with a circumference of 3.25 mm, a 4" x 4" knitted square with this yarn will be 28 stitches wide and 34 rows high.
All knitters knit differently. Personally, I am a 'tight' knitter, which means that, to reach gauge, I might need to use a 3.5 or 3.75 mm knitting needle. Others are 'loose' knitters, and might need to use a 3.00 or 2.75 mm knitting needle. Still others are special snowflakes and knit perfectly to gauge every time. Bitter? Moi?
Knowing this, you might understand why gauge is so important. If I throw caution to the wind and knit a sweater with the recommended needle size, I might end up with a sweater that's several inches too small for me to wear -- all because my gauge was off. Patterns always specify gauge when it matters; things like toys or knitted genitalia (yes, this is A Thing!) usually don't list a gauge. Size, as it turns out, doesn't often matter.*
Another thing you might notice from the chart is the number '50g': this is the weight of the yarn -- and I don't mean the thickness! No, this is the actual weight: as in, if we put this ball of yarn on a scale, it should weigh 50 grams.
Most yarn is sold in 50 or 100g weights, and the
yardage of these weights will vary by the, um, weight (thickness!!!) of the yarn. For example, 50g of lace yarn might yield 400m of yarn, whereas 50g of bulky yarn might yield 100m. Often, a 50g ball will actually be closer to 51 or 52g in weight; my theory is that manufacturers add a little extra length, to account for any stretching (and therefore skewing-of-length) in the process of splitting yarn into balls or skeins. Speaking for myself, I always add an extra yard of two to the yarn I
sell.
If you've seen any of my recent pattern publications, you know that I've been featuring multiple colors within a single design. I needed to include how much yardage of each color was necessary for folks to be able to knit my patterns. I did this by converting the yarn weights to yardage.
Still with me? Let's break this down, using my Hat for Matt (
Estrella Hat) as an example -- the blue one:
There are three shades of blue that make up the body of the hat. This particular yarn is listed as 50g per 108yd of yarn -- this means that every yard of this yarn weighs 2.16g.
The main blue started at 52g in weight, and ended at 23g. Thus, I used 29g of yarn. To figure out how many yards that is, we multiply 29 (grams used) by 2.16 (grams per yard of yarn) = 62.64. I rounded up to 65 yds of the main blue yarn required when I wrote the pattern, for the same reason manufacturers add a gram or two to their yarns.
And there you have it: way more than you ever wanted to know about yarn weight, and are sorry that you asked about.
*Grrrrroan. Sorry, I couldn't help myself.
