What Is Crimp In Wool? (And why it matters!)

Wool crimp. It’ another term that you hear a lot about, especially if you are shopping around for different wools to experiment with, but what exactly does it mean?

And, more importantly, why does it matter to you and your handspinning?

Crimp is the natural wave in each individual fiber of wool. The amount of crimp in the wool varies by breed and individual sheep. Fine wools have more crimps per inch than medium or long wools. Crimp is the reason wool fibers grab together when spinning and gives you the natural springiness or bounce back in the yarn.

When you are first getting started spinning, you don’t think a lot about crimp, you just want an easy to work with wool.

But, when you get a bit of experience, you start to pick wools that will fit your end project. Now, crimp matters!

What Is Staple Length? goes over one of the other main characteristics of wool, how long the fibers are!

New to spinning and want some help? Try my Beginning Spinner Course, it has simple, step by step instructions and is designed to take you from beginner to confident spinner!

What is crimp in wool?

Crimp is the repeated natural kinks or waviness of a wool fiber.

The sheep grows wool with a specific amount of crimp that is fairly consistent throughout her life, however the crimp over parts of her body can vary.

You can think of crimp like a spring, when you push on a spring, it compresses, but then when you let off of the spring, it bounces back to original shape. This bounce back is what crimp does for wool.

It’s actually pretty easy to see which breeds have a higher crimp, because on the sheep the wool will stick straight out in all directions, like a cotton ball.

Breeds like Merino and Rambouillet have higher levels of crimp in their wool.

Sheep that have wool that parts in the middle and falls to the sides also have lower crimp.

Breeds like Lincoln Longwool or Wensleydale have wool that falls over like hair, with very little crimp.

New Mexico State University has a nice article all about wool grades with great pictures of the crimp of a few different breed specific wools.

Do all sheep wools have crimp?

All sheep wools will have some crimp, but the amount will vary significantly with the breed. In general, fine wools have a lot of crimp and long wools have very little crimp.

locks of black wool
The crimp of this wool is easy to see, especially in the flick carded locks in the middle and top.

What does crimp do for handspinning?

Crimp is the reason you can spin wool easier than other fibers, crimp helps the wool kind of grab the other fibers so it doesn’t all slip up into the wheel!

Crimp also provides the “poof” of wool yarn that is so insulating. All those little zigzags don’t quite mesh together when spinning, which is great, since this is where little bits of air are trapped in the yarn.

The tiny bubbles of trapped air give the insulating property of wool that you love for cozy hats and mittens!

Crimp in wool allows you to spin yarns that are resilient (spring back to shape)

The springiness of yarns that you spin is also determined by crimp of the wool that you started with. A springy or resilient yarn is on that will bounce back into shape.

Bounce back is super important in projects that you want to stretch a bit to use, like a hat, but you want them to stay snug, meaning the hat is trying to go back to the original shape, this is what holds it snug on your head.

If you have ever tried to make a hat out of a high luster yarn, yarns also that have very little crimp, you’ll notice that the wool is almost slippery, (which feels nice, actually).

But…yarns with little crimp will make a hat that will not try to hug your head, it will just keep expanding and be super loose. Why? Without crimp, the fibers do not have the “memory” that you need to keep shape.

I have experimented with a variety of wools, usually picked because I thought the fleece was pretty, rather than I thought the fleece would work well for my end goal.

This is how I end up with a bunch of weird shaped hats!

I tend to like the looks of high luster wools, which have little crimp, so little memory or bounce back, which makes them not the greatest choice for hats, but wonderful to spin!

New to spinning and want some help? Try my Beginning Spinner Course, it has simple, step by step instructions and is designed to take you from beginner to confident spinner!

Different amounts of crimp per sheep

Not only are there different amounts of wool crimp per breed, there are also different amounts of crimp per animal, when compared to other sheep of the same breed.

For example: a fine wool breed like a Merino will always have a fine wool with a lot of crimp, from when the sheep is a lamb until the sheep dies, the crimp will remain pretty much the same.

The type of Merino will determine the crimp of the wool. Merino can vary from 20-12 crimps per inch, depending upon the type of Merino.

Fleeces have crimp variation

The entire fleece of the sheep will not be exactly the same, generally the wool on the britch (back of rear leg) is a bit coarser than the rest of the fleece.

Higher quality fleeces have consistent wool over more of the sheep’s body.

Is Merino Hard To Spin? goes over the reasons why you might consider merino for your next project, merino is known for it’s nice, uniform crimp!

A sheep can have sections of the fleece that vary in wool characteristics

Some breeds of sheep, the more “primitive breeds”, can have sections of the fleece that are very different from the rest of the fleece.

These sections can be segregated into spots, like the Jacob, or two distinct fiber types, like Icelandic.

On the Jacob fleece I got from my dad, the white spots were noticeably different from the brown spots. Next shearing will be the same, with two distinct fiber crimps on the same sheep.

To spin the fleece, I just segregated the fiber by color and pulled off brown or white, depending upon which yarn color I wanted.

I could have spun them together and gotten more of a heather type yarn, but I just wanted to get a bit of color variation for my project so I kept the colored sections separate.

A Jacob sheep will keep her fleece characteristics pretty much the same throughout her life, with the exception of varying crimp in different sections of the fleece.

For this sheep, the brown was finer wool than the white sections.

washed white kid mohair
Here is some washed kid mohair, notice how much less crimp it has than the black wool above!

Other fiber animals have crimp

Other animals that we use for fiber also have crimp to their coats.

An alpaca fiber can go from 12-2 crimps per inch, once again, depending upon the alpaca’s breeding. Alpaca will generally have less crimp than most finer wools.

Maybe you have considered incorporating some of your pet’s hair into a yarn? Because of crimp, that works, too! The more crimp the hair has, the easier it will be to put in the yarn.

Any fiber with lower levels of crimp is going to be more challenging to spin if it has a shorter staple, it just won’t have much grab.

To make spinning easier, these less crimpy fibers can be blended with a easier to spin wool, to give the mixed fiber the crimp it needs to stay together for spinning and hold shape as a finished project.

New to spinning and want some help? Try my Beginning Spinner Course, it has simple, step by step instructions and is designed to take you from beginner to confident spinner!


Alpaca Consulting USA by Cameron Holt, I used the crimps per inch of alpaca and merino wool chart page 4

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