Why does Wool Shrink?

At one point we all have experienced our favorite sweater or any garment shrinking after a wash. Even though it wasn’t intentional you lost your favorite sweater and you cannot do anything about it. It keeps you wondering what went wrong that resulted in your garment shrinking. Well, don’t worry we have prepared this blog to make you aware of what went wrong and how you can prevent that from happening again. First of all, let’s look at the structure of the wool fiber.

Structure of the Fiber

The fibers of animals are not smooth. There are scales on every strand of the fiber. When any sort of external force or agitation is applied then the scales of fibers can also lock with each other. This is why the wool felts or shrinks in size. Fibers with larger scales can shrink more easily than fibers with small scales. So, the structure of the wool is one of the main factors that cause the fibers to shrink. But don’t worry, it can be prevented. There are different tips that can help you to prevent your wool from shrinking. But before that let us find out how you can shrink it.

Culprits Behind Shrinking

Wool is one of the durable fabrics but it is not safe to shrinkage. Here are the three main culprits behind the reason that causes the wool fibers to shrink. They are:


When the fiber of the wool comes in contact with moisture the fiber starts to expand. The gap that is caused due to the expansion is filled with moisture and causes the fiber to tighten up. So, when the wool is then allowed to dry naturally the fabric will experience some sort of shrinking. The shrinking won’t be extreme but there will be minimal shrinkage to the fabric.


Heat is the main cause of shrinkage. When the fibers of the wool come in contact with any sort of heat, it causes the fiber to contract. The scale of the fiber minimizes and so the fiber shrinks.   So, it is recommended to not use any sort of heat on the woolen products. If it does come in contact then there is a high chance that the garment would get damaged.


When agitation is applied to the fabric it causes the fiber to stretch beyond its original length. The fibers also won’t align in the same direction. When it is a cold wash, it doesn’t create any problem but if heat is applied then it causes the fibers to flare out and snag onto each other. The wool gets intertwined with each other and the fibers shrink in size.

Different types of Shrinkage

The shrinkage of the fabric can differ on the stress that it is exposed to. It can depend upon the heat, mechanical, and chemicals on how the fabric shrinks. It can be intentional as well as a mistake. The Shrinkage also can differ from one natural fiber to another. So, let’s look at different types of shrinkage that can occur. There are three different types of shrinkage.  They are:


In the woolen world,  felting is a common word that is often heard. It is the process of matting the fibers together to form a piece of fabric. Different external forces like heat and agitation are provided to feel the fibers together. Once the felting process is completed the size of the wool also shrinks by about forty percent.


This type of shrinkage is caused due to mechanical strain put on the fiber. Like washing machines, when the clothes are kept inside the washing machine the movement of the washing machine causes the fibers to curl up and tangle with each other.


This is the process of immediate release of the tension when the fabric is stretched out. This happens when the tension within the natural fabrics is threatened due to external processes like washing and warm water. The fabric’s size then gets reduces by a certain percentage.

How to Wash Wool Without Shrinking?

Now you know what causes the wool to shrink. So, when cleaning them you want to be as careful as you can be.  Wools have natural dirt repellant and anti-bacterial properties, so you don’t need to clean or wash the garment as often as other garments. This doesn’t mean that you can go on without washing it, sometimes it needs a good soak and a rinse. So, make sure you do that depending on the condition of your woolen garment. If you are a beginner then here are some tips you will need to follow to keep the wool clean without damaging it.

Use Fresh and Cool Water

Use fresh and clean water when you are washing the wool. For example, if you are washing many garments at once then we recommend you to start with fresh water for every garment. This makes sure that you get rid of previous dyes and the chemicals that would damage your garment. Also, make sure the water is cold, not warm or hot. As we have already mentioned before heat is one of the main culprits to shrink the wool garment. So, hot water can also shrink the garment.

Wash Gently

This also crucial steps to cleaning your wool garment. Make sure you do not use any sort of harsh movement when washing the garment. This makes sure that agitation is minimal as well as the damage. Wools have naturally dirt repellant, so you wouldn’t need to apply harsh force to clean out the dirt. A simple soak is perfect for the wool to clean the dirt nicely.

Thorough Rinse

Make sure you get rid of all the soap remnants when cleaning the woo garments. If the remnants are not removed properly then the chemical from the soap would damage the garment in the long run. So, using the cold water rinse the garment repeatedly. Until you notice clean water running from the garment rinse it repeatedly.

Dry Carefully

Before using the garment make sure it is dried properly. We do not recommend using external heat from the dryer or iron. It is best to let the garment air dry. Do not keep it under direct sunlight as it can damage your wool garment. So, the best way to dry your woolen garment is by keeping it in a shady but warm place to dry it. make sure the garment is completely dry. If it is not dried properly then bacteria could build on it.

How to Unshrink Wool?

What if you did end up shrinking your woolen garments? Don’t worry there are some ways you can unshrink your wool. You can use stuff that you can find easily in your home like hair conditioner or fabric conditioner. So, you don’t need any special or extra knowledge to do so. The process of unshrinking the wool takes more time than it takes you ot shrink it. So, you need to have great patience and effort to unshrink it. You might wonder if it is worthy to rescue the damaged piece. Well, that depends on yourself. So, let’s look at some ways you can unshrink your woolen garments:


This is one of the common methods used by many knitters to give shape to their knitted final product. In this method, the fiber of the woolen garments is relaxed using a steamer or cool water. After the fiber is relaxed it is stretched on a rubber mat until the desired shape is obtained. Since this method allows the person to have control over the end result it is one of the favored methods. Many professionals like dry cleaners and knitters use this method to stretch the garments that have shrunk.

Hair Conditioner

After a hair wash when we use hair conditioner on our hair, it makes it so soft and silky. Like that hair, the conditioner can also do the same to the fibers of the wool. Since hair conditioners are designed to soften hair that has proteins, it can the woool fiber as well which is made of protein. You just need to soak the wool garment into the conditioner solution for a few minutes rinse it thoroughly. After rinsing make sure you squeeze out the moisture from the garment completely and place it on the clean towel then stretch out gently and let it air dry.

Fabric Softener

if you have a fabric softener at your home then you can use that as well to relax and loosen the fiber of the wool and then stretch it. The process is kinda similar to using a hair conditioner. You just soak the garment for a few minutes and then gently stretch it. Make sure to air dry and not use any external force dry the garment.

Epsom Salt

This is one of the oldest methods used by the old folks. Although this method is less popular, still many older folks swear by this method to stretch the fabric. Epsom salt has the ability to relax the fiber. So, if you have some in your household then you can use them as well. You can just place the garment along with one cup of Epsom salt in cool water and delicate cycle. After the cycle is complete carefully take out the garment from the machine. Like every other method place it on a flat surface and stretch it to its original shape. Be careful when you are stretching circular corners. Pull the edges gently and work your way around. After you have your desired shape let it air dry.


Vinegar is easily found around our home. It not only has properties to make the fabric itch-proof but also makes the fabric soft. So, the fibers become soft and can be stretched into the desired shape. What you need to do is just soak the fabric in the vinegar solution for 15 to 30 minutes. The duration can differ depending on the size and the quality of the wool. Then rinse the solution out from the garment and place it on a flat surface. Make sure all the water is squeezed out from the garment. Spread out on a clean surface and align it into the desired shape and tug it. This allows the garment to dry in its new shape.


We all have the experience of shrinking our woolen garments once in our life. Like we learn from our mistakes, hope you’re able to learn from this blog. We hope you wouldn’t repeat the same mistakes again. You shouldn’t also wear your favorite piece of woolen garment for the fear of damaging it. Don’t worry, you can rescue your damaged or shrunk garment.    
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Arun Sapkota

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