How Much Does Cotton Shrink

All fabrics are different, but the one thing they have in common is that they are made from woven fibres. One of the most important distinctions between fabrics is whether they are natural or synthetic. As you may recognise, polyester, nylon and acrylic are all synthetic fabrics, while cotton is a natural fibre.

Cotton is a great material! It's comfortable, durable and widely available. However, cotton is also prone to shrinkage.

Does cotton shrink? Most cotton items are 'pre-shrunk' during the manufacturing process and will stay close to their original size after each wash but in worst case they could shrink up to 5% but this could be as much as 20% if the garment was not 'pre-shrunk'.

How much does cotton shrink? That depends on a variety of factors. The science behind shrinkage can be best explained by first understanding how cotton is made.

In essence, when cotton is spun into a thread, raw cotton fibres are stretched and tension is created to make the weave.

An interesting fact about cotton is how much water it can retain, cotton can absorb upto 30 times its own weight and becomes more elastic. This combined with high temperatures (for example in your washing machine), this can cause the fibres to lose their tension and therefore result in shrinkage.

Now that you know the science behind how cotton shrinks, it is possible to manipulate it to suit your sizing needs, but first, we need to understand how much cotton shrinks and how this may vary.

How much does cotton shrink?

The answer to the question 'How much does cotton shrink?' depends largely on whether the items have been pre-shrunk before purchase.

You may be surprised to hear that most manufacturers do this for the buyer's convenience. After all, nobody wants to buy a new item that is just the right size only to have it shrink in the wash.

Most care labels should indicate whether the cotton has been pre-shrunk. If it has, you can expect shrinkage by only 2-5%, if it hasn't, you should prepare for more.

What Does Pre-Shrunk Mean?

When an item indicates it has been "pre-shrunk" on its label, it means the garment has been treated during its manufacture with a process that would protect the garment from shrinking when you wash it at home. This is not a 100% guarantee that the item will not shrink further however.

The pre-shrinking process is usually a combination of one or more factors which involve; high heat; moisture; or agitating the fibers with a machine that would reduce the spacing between the fibers.

How much does 100% cotton shrink?

Most natural fabrics are prone to shrinkage when exposed to high temperatures. Given 100% cotton is not a blend, it is more likely to shrink that its blended counterparts assuming it's not been pre-shrunk.

As a guideline, you can still expect pre-shrunk 100% cotton to shrink by 2-5% or slightly more, so make sure to check the tag to see if the item you're looking at has been pre-shrunk before.

How much does cotton shrink if it's organic?

Organic cotton is not any different from any other cotton in this regard, so you can follow the information above for what you can expect.

If you want to minimise or encourage shrinkage, the section below provides some thorough guidance to manipulate the fabric.

How can I avoid cotton shrinking?

If you have any clothes or garments you want to keep from shrinking, there are a number of steps you can take. It is important to note that each item is different, so always follow the instructions on the care label for the best results.

Use the appropriate washing machine settings

Most washing machines today have settings to stop your clothes from shrinking. You should choose a gentle cycle for your garments combined with a soft detergent and a low temperature (minus 30C, or better yet, cold). Setting the cycle to delicate will minimise the heat and protect your cotton items.

Tumble dry on low only

Dryers remove moisture from your clothes by using heat and movement. As we have discussed, most natural materials such as cotton will shrink under high temperatures.

In a dryer, as the clothes spin in a hot and enclosed area, the fibres constrict and you end up with a shrunken garment. To avoid this, you should set your dryer to the lowest heat setting and tumble dry until completely dry.

Can I increase shrinkage?

Many people spend a lot of time, effort and care to protect their clothes from shrinking, so why would anyone deliberately shrink their garments?

While it may appear ludicrous to some, there are good reasons why someone may need to shrink an item or two. From weight loss to buying things in the wrong size, there are things you can do to increase shrinkage.

Do note that these will only work on clothes that have not been pre-shrunk, so if you're buying something with the intention of downsizing, make sure to look at the label first.

How to shrink cotton?

It is important to be aware that any shrinkage you achieve is permanent, so make sure you want to proceed. The first step in this process is to select your item, which should not have been pre-shrunk. If it has, this may not work at all or you may get uneven shrinkage.

1. To begin, boil a large pot of clean water making sure to leave enough room for the fabric.
2. Carefully place the item of your choice in the water, and stir to make sure it is completely soaked.
3. Leave the garment in the pot for about five minutes
4. Remove the item from the water and throw it in a dryer
5. Use the highest possible setting and tumble dry until all moisture has been removed

With this method, you can expect your clothes to shrink up to two sizes.

In some cases, your clothes may lose a little bit of colour or they may bleed. For this reason, it is crucial that you shrink items one at a time.

You can increase the chances of keeping your attire bright and vibrant by adding some white vinegar to the water, but be aware colour loss may happen. Likewise, if you want to shrink your clothes less than two sizes, boil the water and let it sit for five minutes before adding your clothing in.

If your cotton has shrunk but not enough, repeat the above process until you achieve your desired size.

It is normal for clothes and other cotton items to shrink naturally over time. Now that you know why shrinkage occurs and how much does cotton shrink, you can minimise it and maximise it as you wish.