Does Yarn Shrink When Washed? (4 Different Yarns Explored)

A huge part of planning for your next project is what kind of yarn you will use. Whether it’s a hat or a sweater, eventually you’re going to want to wash it. So, does yarn shrink when washed?

Yarns made out of animal fibers such as wool and alpaca will shrink if washed in a washing machine but not if you hand wash them without agitation. Yarns made out of plant fibers like cotton, ramie, or flax will not shrink when washed. Yarn made from man-made fibers, like acrylic, will not shrink when washed.

In this article, we’ll look closer at wool, alpaca, cotton, and acrylic yarns to see if they shrink when washed in a washing machine. Let’s dig in!

Table of Contents

Does Yarn Shrink When Washed?

Does yarn shrink when washed

In order to really show you the details you want about shrinking yarn, I did a little experiment with the most common types of yarn. I knitted a swatch (a square of knitted yarn) of wool yarn, alpaca yarn, cotton yarn, and acrylic yarn. 

I took pictures with a scale before and after I washed them as well as after I put them in the dryer.

When I washed them, I just threw them in with a normal load of laundry set to warm water and with my normal powdered laundry detergent. The only thing out of the ordinary that I did with them was put the swatches in a mesh bag so they would be easier to find in the laundry.  

For the sake of the experiment, I just used regular laundry detergent. But, when washing wool or alpaca, you normally want to wash them with a wool wash.

Let’s talk about the results!

Does Acrylic Yarn Shrink When Washed?

Does acrylic yarn shrink when washed

Acrylic yarn is made to mimic the warmth and softness of wool but, because it’s a synthetic fiber, it has some distinct differences. 

First, as you can see from the picture, acrylic yarn doesn’t shrink when it’s washed. 

The swatch was the same size after I washed it and after I took it out of the dryer. After I took it out of the dryer, it was slightly curled. This means that the fibers have tightened up a little bit.

But, don’t worry, this isn’t bad. If you have a hat or anything made out of acrylic yarn, it will just be a little tighter if you put it on after you wash it. After you wear it for a little bit though, the fibers will loosen back up and it will be just the same as it was. 

This makes acrylic a great option for things that you want to be able to wash a lot without worrying about them changing shape. However, acrylic isn’t good for things like socks or dishcloths because it doesn’t absorb moisture very well. 

On the opposite side of the spectrum, acrylic can be blocked and stretched a little using steam, check out this post for more info: Does Acrylic Yarn Stretch? How to Block Acrylic Yarn

On to the next yarn!

Does Cotton Yarn Shrink When Washed?

does cotton yarn shrink when washed

Cotton yarn is much the same as acrylic. It doesn’t change size or shrink when washed. The main thing with cotton yarn is that the yarn gets fluffed up when washed. 

What I mean by this is, the yarn poofs up and fills in any gaps that remain between your stitches if you make something out of it. This is especially noticeable if you weave something out of cotton. 

But, this fluffing isn’t a bad thing. It softens the cotton fibers which makes it softer to the touch and ready to absorb moisture. 

Cotton yarn is another great option for things that you want to be able to wash frequently and not have to worry about shrinking. 

However, cotton yarn has no stretch, so it’s not very good for form-fitting objects like hats and socks. It also isn’t very insulating. But it’s excellent for dishcloths and towels because cotton is very absorbent. 

Two yarns down, two to go. 

Does Alpaca Yarn Shrink When Washed?

does alpaca yarn shrink when washed

Alpaca yarn is considered a more expensive yarn and is usually only used for pretty special projects. Because of its specialty and fiber structure, alpaca is usually blended with other fibers. 

I didn’t have any alpaca yarn but I did have some alpaca fiber. So, I made some 100% Alpaca yarn on my spinning wheel just for this experiment. 

Alpaca yarn will felt and shrink if washed in a washing machine. Because alpaca is an animal fiber, its structure causes it to seize up when exposed to heat and agitation. Washing machines cause a lot of heat and agitation. 

As you can see in the picture, after just the wash cycle the Alpaca was already matted together. I actually had to pull the swatch apart from itself in order to lay it flat. 

Alpaca is an extremely warm fiber. It’s great for insulation and warmth in the winter. It’s often blended with wool because wool has some natural water-resistant properties. An alpaca and wool blend hat is the bomb in the winter. 

But, because of its tendency to felt when washed, you have to wash it carefully with no agitation and lay it flat to dry. 

Here’s a great video about why things felt when washed. Even though the video is about wool, the science is the same for any animal or protein fiber such as Alpaca.

Last but not least, let’s talk about wool. 

Does Wool Yarn Shrink When Washed?

does wool yarn shrink when washed

Wool is the most common yarn used for warm winter clothes such as hats, sweaters, and mittens. 

However, the biggest reason people worry about using wool in projects is that it can shrink when washed. 

This is proven in the little experiment I did. As you can see, the wool didn’t shrink very much. But, it didn’t shrink partially because it was already knit very tightly which means there wasn’t very much space for it to seize up.

If you have a looser knit wool item, it will shrink more. 

It shrank some after the wash and then it shrank a little bit more after the dryer.

The wool also became felted and matted together. While this won’t take away the warmness of the wool, it does take away the softness and springiness. 

Some projects are created for purpose of felting, such as wool felt bags. This can create an awesome effect, but when you’re making these objects, you have to take the amount of shrink into account. 

Wool is a super awesome fiber that has some amazing properties. If you want to know some crazy wool facts, check out this other post I wrote.

Wrap up

Well, I hope my yarn experiment has been useful to you. I had a lot of fun seeing the differences in these yarns. Let’s go over what happened to them when I threw them in the wash. 

Acrylic yarn and cotton yarn will not shrink in the wash. If anything happens to these two types of yarn, they may tighten up a little bit, but they will relax again after a little bit of use. 

Wool and alpaca yarn, on the other hand, will shrink and felt when put in the washing machine. That doesn’t mean you shouldn’t use this type of yarn though! 

With all their awesome properties, you wouldn’t want to miss out on wool and alpaca yarn just because of a silly washing machine. 

You can wash garments made out of these fibers by hand to ensure they don’t shrink and then you’ll be A-OK. 

With your newfound yarn knowledge, go make something awesome!

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