Wool is an amazing fabric to have in your wardrobe. It feels great against the skin, has excellent insulating abilities while still remaining breathable and comfortable to wear, making it perfect for all occasions.
However, wool is a difficult fiber to manage, so when you finally find a nice garment made of wool, it can be rather disappointing if it shrinks the first time you wash it.
So, does wool shrink? Yes, wool can shrink in the washing machine or the dryer due to the combination of heat and friction. This could happen to any woolen garment that you wash.
The good news is that there are some simple ways to prevent your wool from shrinking so you can keep your favorite garments in tip-top shape. This guide will tell you some things you should know about caring for wool garments and teach you how to wash your wool without shrinking it.
Does Wool Shrink?
100% wool can shrink when met with heat and friction. Wool is a protein-based natural fiber that comes from animals such as sheep (such as Merino and alpaca) and goats (such as cashmere wool).
Wool is made up of protein fibers, which have microscopic hooks. When the yarn is spun into thread, and the thread is woven into the fabric, these little hooks interlock to lock the fabric together and give it its durability and strength.
In order to make a piece of wool fabric, it has to be washed and dried. This process makes the fibers relax and straighten out so that they’re all at their natural length. The fabric loses some of its bulk in this process, but it doesn’t shrink in length or width.
The problem comes when you try to wash a wool garment for the first time after you’ve purchased it. You may notice that when you take your new woolen clothes out of their dryer, they seem smaller than they did before they went in.
That’s because, during normal washing, there are two things that happen: heat and friction. The heat of the water and the dryer, combined with the friction caused inside a normal cycle, causes the fibers to compress, which leads to the shrinkage that you observe after washing.
This is the reason most manufacturers recommend that wool clothing be hand washed and airdried to minimize shrinkage.
How Much Does Wool Shrink?
If you accidentally throw your woolen garment in the washer and dryer, your wool can shrink dramatically from its original size. There are a few factors that determine how much wool will shrink, including what type of wool is used to make the garment, how it was processed, and how it is washed.
Merino wool shrinks less than other types of wool, such as cashmere or alpaca, because Merino has longer and smoother wool fibers that are more heat-resistant. Wool blends also shrink less than 100% wool, but it also depends on the type of blend and the wool percentage in the blend.
Shrinking typically happens when woolen fabrics are washed in hot water and then put into a hot dryer. This removes moisture from the fibers and causes them to tighten up and become smaller.
In most cases and for most types of 100% wool, the shrinkage is also quite reversible, so you don’t have to worry about permanently ruining your wool if you accidentally put it in the dryer once or twice.
The friction caused inside the washer and dryer can also lead to pilling — balls of fabric that have been rubbed together and become loose from the garment. Wool has scales that naturally lock together like Velcro, and in some cases, your wool sweater can become felted because of this process.
Does Wool Shrink When Washed?
Although most people think that wool shrinks in the wash, water is not the main culprit that makes wool shrink.
Wool is made up of a series of interlocking fibers that are held together by scales. These scales help keep moisture away from the wool fiber, which is why wool naturally repels water.
If you put wool in hot water, the heat will open up the scales and allow water to penetrate into the fiber. Wool fiber swells when it becomes wet and then contracts when it dries. This is what causes wool to shrink when you wash it.
If don’t want your woolen items to shrink, you should avoid washing them in really hot water. The main culprit here is the heat, so handwashing in cool or slightly warm water is always recommended for wool.
Wool is not the only fabric that shrinks when it’s washed or dried. Cotton, linen, rayon, and silk all shrink when exposed to high temperatures.
However, this won’t cause these fabrics to shrink as much as wool because they don’t have scales like wool does that can be opened up by heat.
If you think handwashing wool every time is too much, you can opt for superwash wool. This type of wool is treated so that it won’t shrink in the wash as regular wool does. It has a unique design that prevents the wool scales from getting caught on one another, thus preventing shrinkage.
Keep in mind that the soap you use can also damage wool. Some detergents have enzymes that can consume the protein-based fibers, which can cause the wool to become distorted and shrink in the process. It’s always best to check whether your detergent is safe to use for wool and other protein-based fibers.
Does Wool Shrink In The Dryer?
Because your drier uses heat and friction to dry your clothes, your wool does shrink in the dryer, even the superwash wool that has been treated to withstand the washing machine.
Even when you use the low-heat level, the machine does use friction to dry your wool, which can cause pilling and felting.
The coating on top of a superwash garment should not protect the wool from damage caused by friction. The superwash treatment doesn’t prevent the wool from getting agitated by friction and heat, so even if superwash wool is safe for washing machines, it should still be kept away from the dryer.
Airdrying wool garments is much better for them since it prevents warping and shrinking. After washing your wool, just make sure that your garment is not dripping wet by gently squeezing the fabric, and then lay it flat on a towel to air dry.
Does Wool Shrink When It Gets Wet?
Wool does not shrink when it is submerged in water. Like other types of fabric, it just absorbs the water and returns to its original size when it is completely dry.
The problem occurs when wool is met with heat and friction. Hot water causes the fibers to expand, but the problem gets worse when you also agitate the fabric with movement and friction.
In this environment, the protein scales in the wool can catch on to each other and become interlocking, which results in shrinkage and sometimes even felt.
Water can expand the fibers of wool; your wool will still return to its normal shape once it is dry. However, since wool is more delicate when it’s wet, it’s best to hand wash the garment and lay it out to air dry so that you don’t damage the fabric when it’s at its most delicate state.
Do Wool Blends Shrink?
Wool fibers can also be blended with other types of fibers, especially synthetic fibers such as polyester or acrylic, to enhance their durability.
Wool blends can shrink depending on the amount of wool in them. In most cases, the higher the wool content, the more shrinkage they will experience. If the wool blend has more than 50% wool, it will shrink similarly to 100 percent wool.
When a wool blend has less than 50% wool content, the other fibers in the garment will prevent the wool fibers from shrinking in the wash. In most cases, a 5% wool blend with synthetic fiber will not shrink significantly.
Note that other types of natural fibers, such as cotton, are also prone to shrinkage. If you have a wool/cotton blend, it will shrink as much as 100 percent wool or 100 percent cotton will.
Regardless of the fiber content, high heat and careless treatments can damage any fabric’s properties. When you take care of the fabric, it’s best to follow the care instructions on the tag so that your fabric will last longer in your closet.
How To Unshrink Wool
If you accidentally shrink a woolen garment, don’t worry; the shrinkage is most likely not permanent. It can be reversed by loosening the protein scales to get the garment back to its original size.
Wool has memory, which means that it will always try to return to its normal shape when it has been distorted in some way. To activate a wool garment’s memory, you can loosen the wool fibers by opening them up with water and a relaxer (such as a hair conditioner or fabric softener). This method will restore its shape and size.
Human hair is made of proteins that are similar to wool fibers. The only difference is that the protein scales in this hair are smooth and flat, but because they’re similar, you can use a hair conditioner to open up the wool fibers.
If you don’t have a hair conditioner, using baby shampoo or a mild fabric softener will also get the job done.
To reverse the shrinkage, soak your wool in a solution of water and ½ cup of hair conditioner for around 15 minutes. After this time, remove the excess water by gently squeezing your garment and rinsing your garment with cool water to remove the hair conditioner from the wool.
After the garment is clean, you can lay it on a flat surface and gently stretch the garment to loosen up the fibers. If you have sewing pins, you can also use the pins to pin your wool garment to a flat towel or mat to keep the garment in shape as it dries.
Then, you can let the garment air dry, and it should reverse back to its original size when the moisture is completely gone.
Keep in mind that this process won’t do much to help with wool that has become felted. This is because felting is a permanent, irreversible process where wool fibers become interlocked in crisscrossing patterns that cannot be reversed, so if your garment has felted, there’s not much that you can do to restore it.
How To Take Care Of Your Wool To Avoid Shrinkage
If you don’t want your wool to shrink in the wash, there are a few things that you can do to keep your wool brand new.
One of the great advantages of wool is that it stays fresh without being washed for a long time. This means that they are significantly less prone to damage than other fabrics, especially if you take care of them right.
This means you don’t have to wash your wool after every use, as it takes a while for them to get dirty. Washing your wool infrequently will minimize the damage caused by the wash.
However, wool does stain very easily, so if you accidentally spill on your wool, you do need to spot-treat the stained area right away to prevent the stains from shrinking into the fibers and becoming stubborn to treat.
When it comes to washing your wool, there are many ways to get them done safely and effectively. You don’t have to take them to the dry cleaner, and in some cases, the chemicals used in dry cleaning can also be quite damaging to your wool’s softness and appearance.
If you want to wash your wool, gently handwashing them in cool water with mild soap and airdrying would do the trick.
Many modern wool fabrics, such as superwash wool or some wool blends, are safe to use in the washer, as long as they are washed with a gentle cycle with a mild detergent and cool water. Afterward, you should still make sure to air dry the garment on a flat surface to prevent shrinkage.
If you are unsure about how to handle your wool, check the garment tag or fabric label to make sure that it’s safe to put in the washing machine.
When washing wool clothes in the washing machine, put them in a mesh laundry bag (similar to washing lingerie) before putting them in the washing machine, and use a delicate cycle. This will minimize the friction that your wool has to endure during a wash cycle.
You can also wash your wool with other fibers, like synthetic fibers and cotton too. You don’t have to separate them in the wash, but if you do wash them together, make sure to separate light and dark clothes so that the colors don’t bleed on one another.
When you airdry your wool, lay them out on a flat surface to dry, don’t hang them with a hanger. This is because wet wool garments can be very heavy, and gravity can pull down the garment that has been hung on a hanger, causing the top part to become very stretched out and distorted.
Similarly, when you need to store your wool, make sure to keep them folded rather than hung.
Make sure that your wool garment is completely dry before putting them away to prevent mold and mildew, and store them in a cotton bag in a dry, cool place before the next use. This is especially true for expensive, delicate wool such as cashmere.
To learn how to wash a wool or cashmere sweater, watch this video by The Woolmark Company.
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