
There’s a lot of great information that comes with your yarn, everything from yardage to what it’s made of which is why it’s extremely important to know how to read a yarn label.
The anatomy of the label tends to change from brand to brand and even between yarn types from the same brand. There’s no set schematic for every label, but I can show you what to look for.
Label info
Yarn weight
You’ll probably notice that every skein of yarn has a number on it. The scale goes from 0 to 7, these numbers are industry standards for yarn weights.
The numbers are generally found on a picture of a skein of yarn, but the placement is pretty much up for grabs.

These numbers can help with determining hook size and achieving various affects. For example, if you want a fabric that drapes well, you could use a lighter weight yarn, such as a 3, with a J/6mm hook. If you want a tight stitch, like for amrgurmie, a worsted weight 4 with a G/4mm hook would be better.
Material
What a yarn is made of can determine what you use it for. For example, if you’re making a potholder you don’t necessarily want to be using wool, because it will felt everytime you throw it in the wash. You don’t want to use synthetic materials like acrylic or polyester, or else it will melt! I find cotton to work the best for potholders (free potholder pattern)
You normally find a percentile of the materials used in the yarn close to the yardage and weight(ounces and grams).

It also help with preference, you may only want to use natural yarns like cottons, wools, bamboo, and the like. Or you might like the feel of polyester, nylon, and acrylic better. (Or you could be like me and use them all..)
Yardage and weight
You’re not seeing double, I said weight twice, but this time I’m talking ounces and grams. More important than the weight is the yardage. Depending on the size/bulkiness of the yarn it can get pretty heavy, but might not have all that much in the way of length. Or be really light and have quite a bit of length like the red eyelash yarn.

I personally find the yardage much more useful because it can help you figure out how many skeins you need for your project.
Dye lot and color and brand
I’m combining these because the color name and dye lot really depend on the brand and sub brand. (example: brand:Red Heart, sub brand:With Love)
Colorways can have the same name across brands and sub brands, which is why it’s a good idea to document everything about the yarn from the label into the notebook you’re writing your pattern in or on the pattern pages if you’re using someone else’s pattern.
Dye lots are important to keep track of because, regardless of using the same dye in exact measurements each time they make the dye bath for the batch, the color is never exactly the same. Futher more the yarn, despite being the same material, won’t except it the exact same way. Each new batch of dye gets a dye lot number that makes it much more likely that you’ll have the same color. The placement on the label is usually close to the color name.

You’ll probably come across some brands that have “no dye lot” sometimes they’ll say it where the dye lot would normally be, other times it just won’t have a dye lot number at all. This doesn’t actually mean the yarn doesn’t have a dye lot it just means they do huge batches at a time so it’s less likely that you’ll have multiple lots. However this can be an issue if you’re making a large project and you don’t have enough of that colorway to complete it. I usually buy one more than I think I need just it case.

Crochet/knitting info
This information is usually found right next to the yarn weight. These little charts are quite useful for when you’re making your own patterns or substituting a yarn in a pattern. Looking at the first grey label you’ll see that it says 14 single crochets with 14 rows should give you a 4″×4″ square if it’s made with a K/6.5mm hook. This tells you that if you’re not achieving these measurements you need to correct your gauge/tension. These measurements are normally to achieve a Goldilocks, stitches that aren’t too tight, or too loose, they’re just right.

If you’re using this information to substitute a pattern check out the gauge on your pattern and compare it to this chart on the label, is it close? If so, you might just have to go up or down a hook size to get the same results. This is why you should always swatch your yarn, if you’re worried you won’t have enough for the project you can always frog it once you know you’ve got it right and start your work from there.
Knitters the info is there for you too! Just with your terms and tools.
Washing and care instructions
After you spend all that time making something you don’t want it to be ruined because it was washed incorrectly. You definitely want to make sure you know what these little symbols mean on the label.
The yarn council has a complete list here, but I’ll run you through the ones on the skein below.

The first symbol, the tub with water is for washing instructions, this one says very clearly that the water should be 104 degrees fahrenheit or 40 degrees celsius.
The second symbol, this is the drying symbol, the dot in the middle indicates that it should tumble dry on low heat.
The third sumbol, this one is pretty easy, do not iron this yarn! The iron is probably one of the most recognizable symbol.
The forth symbol, if you see a triangle it’s about bleach and in this case it’s saying not to go anywhere near it with your freshly made garment.
The fifth symbol, circles indicate dry cleaning instructions. The circle with the P in the middle is telling you that this yarn can take any solvent except Trichloroethylene. If you see a circle with an X through it do not dry clean it!
I hope you find this useful, if you have any questions I’ll happy to answer them in the comments below!
I made a little cheat sheet for yarn weight which you can download for free.