The Ultimate Guide to Yarn Types: Fiber & Weight

There are several yarn types and options to choose from when it comes to fiber. The fiber type is a yarn content. It shows what is the yarn made of.

There are three basic types of fibers: Natural, Synthetic and Blended. Natural yarn can be animal (from sheep, goat, camel, caterpillar, rabbit) or plant based (cotton, linen, bamboo, raffia). Synthetic yarns are made artificially of acrylic, nylon, polyester or rayon. Blended yarns are natural and synthetic fibers mixed together. In this post, I will be tackling just four most obvious and most often used types of yarn when it comes to crochet: wool, acrylic, cotton and blends. 

yarn types: fiber

When you say WOOL, I say sheep! But that’s not necessarily the case. There are some other, generally considered more luxurious types of wool, such as alpaca (camel), cashmere and mohair (goat), angora (rabbit) or silk (insects).

In general, wool is elastic, breathable, absorbent (it will keep you dry), long-lasting and requires less washing (thanks to its antibacterial characteristics!). It can sometimes feel itchy if you wear it next to your skin and some people are allergic to it.

It is the best for winter garments and accessories, as well as socks. It should be washed at law temperatures, and more importantly at lower spin cycles, because it could felt otherwise.

COTTON is absorbent, strong, not really elastic and gives a clear stitch definition. It is an excellent choice for your home deco crochet projects that should be strong and sturdy like wall hangers, plant hangers, bathroom and kitchen items such as potholders and coasters, washcloths and scrubbies. It is also good for light, summer projects. If you want your item to hold shape – you should use cotton.

ACRYLIC yarn is crisp and soft, it has drape and it is resistant to shrinkage. It is not really absorbent, but it dries quite fast. It is often anti-pilling, even and consistent. Acrylic yarn is widely available, strong and machine washable and, holds up well when used daily.  All these characteristics, along with the fact that it is more affordable, make acrylic very popular type of yarn. It’s probably the most versatile of all yarns. It is used for home deco projects, from blankets and pillows to garments and accessories. On the other hand, it’s basically plastic. Never use it when something involves heat. Talking about plastic, if you would like to know something about more ecological and exotic yarn types, here is an interesting article I found by Raffamusa Designs.

I need to say that my favorites are BLENDS. Blends are basically the mix of two or sometimes more different fibers in one yarn. In my opinion, they combine the best of both worlds. Most often you will find cotton-acrylic and wool-acrylic blends in different ratio.

yarn types: weight

YARN WEIGHT: refers to how thick the certain yarn is. It is classified in 8 categories from 0 to 7, where 0 is the thinnest. It is crucial to understand the yarn weight to be able to choose the right yarn, or find the best alternative. I like to define this category further with WPI (wraps per inch). And exactly this category was confusing me the most, because of the variety of names and terms (UK, US, AU and also a few that I’m not really sure which part of the world they belong to) used to define each category. So, having the yarn categories with the same meaning and recommended hook sizes all in one place has worked for me, without getting into the geography of it.

Categories:

0 (1/2 ply, Lace, Cobweb, Light Fingering/Fingering, Size 10 Crochet Thread); Hook 1.5-2.25 mm metric / steel 8-1 regular hook B1 US; WPI 20+. Good for: dollies, lace, delicate and light accessories.

1 (2/3 ply; Sock, Fingering, Baby), Hook 2.25-3.5 mm metric / B–1 to –4 US; WPI 18-20. Good for dollies, lace, baby clothes, socks, light tops.

2 (4/5 ply, Sport, Baby), Hook 3.5-4.5 mm metric / E–4 to 7 US; WPI 15-18. Good for: baby clothes, socks, light summer garments.

3 (8 ply, DK, Light Worsted), Hook 4.5-5.5 mm metric / 7 to I–9 US; WPI 11-14. Good for light sweaters, tops, baby blankets.

4 (10/12 ply, Medium Worsted, Aran, Afgan), Hook 5.5-6.5 mm metric / I–9 to K–10 1⁄2 US; WPI 9-10. Good for: sweaters, hats, scarves, blankets.

5 (12/14 ply, Chunky, Bulky, Craft, Rug), Hook 6.5-9 mm metric / K–10 1⁄2 to M–13 US; WPI 7-8. Good for: hats, sweaters, scarves, blankets, rugs.

6 (14/16 ply, Super Chunky, Super Bulky, Roving) Hook 8-12 mm metric / L–11 to O-16; WPI 5-6. Good for: heavy sweaters, accessories, blankets, rugs.

7 (16+ ply; Roving), Hook 12+ mm metric / O-16 and larger US; WPI 1-4. Good for: finger crochet, supersized sweaters and throws.

wpi

I would like to make an emphasize on WPI here.I am seriously considering adding it to my future patterns as an extra information. I find it to be really good method to categorize the yarn. It is especially useful when I dive into my stash and emerge with some gorgeous yarn without label (the one I was sure I would certainly remember which brand it was).

It is especially useful when trying to find right substitute yarn for your project.

You can see that all 4 yarns are category #6 super bulky, but still have different WPI. 1 and 2 have five, and 3 and 4 have six wraps per inch. Also, Wool-Ease and Superlana Maxi have slightly different fiber composition, but they should give exactly the same gauge. I actually used those two for my Eccentric Beanie and they worked perfectly. You can check out the examples with both yarns.

You can count Wraps Per Inch – loosely wrap the yarn around, well, almost anything (a pencil, a piece of carbon, a ruler…), without overlapping strands and count how many wraps you have in one inch (2.5 cm). You are not counting the length of the yarn here, you want to determine thickness of it, how many strands can fit in one inch. You will find here the approximate WPI for each yarn category.  If your WPI matches, chances are your alternative yarn will be a good match and you shouldn’t have too much trouble meeting the gauge. 

I need to mention here that you can find different WPI clasifications, especialy when it comes to 0-3 categories. You should take it as a guidance only. I suggest you always check the recomended hook size on the yarn label and try out different options, until you find what works the best for you.

As always, you can refer to Craft Yarn Council of America, considered to be an authority in setting global standards and guidelines. You can visit their site for more information.

about ply

Finaly, just a couple of words about PLY. The reason why I am even mentioning this here is the different use of the term that could cause confusion. Some countries (such as Australia, New Zealand and UK) use the number of plies as a shorthand for the thickness of the yarn as you can see above. Nevertheless, in most cases the number of plies has nothing to do with the thickness of the finished yarn. At its most basic, ply refers to the number of strands of yarn twisted together. One ply being worked on its own is usually called single. Plied yarns are considered to be more durable and less susceptible to pilling. 

NOTE: Use the information as a guidance only.