Since almost 80% of clothing purchased in the United States contains spandex, you likely have at least one garment in your wardrobe that contains this stretchy fiber. While it is comfortable and easy to come by, you might be wondering, does spandex shrink?
Spandex is a heat-resistant fiber, but it can shrink in the dryer or when washed. The highest heat settings for most washing machines and dryers are hot enough to shrink spandex fabric. Spandex is also commonly found in fabric blends, which can be more susceptible to shrinkage than spandex alone.
Keeping your spandex stretchy and avoiding shrinkage is easy to do when you know how to care for this fiber. This guide will help you figure out the best way to avoid shrinking your spandex, whether it’s in a fiber blend or on its own.
Does Spandex Shrink?
Like many fabrics, spandex’s greatest enemy is heat. High temperatures will cause spandex to shrink, whether that heat comes from the temperature of the wash water or the dryer.
During manufacturing, machinery puts the individual spandex fibers under a lot of pressure. There is a high twist to the threads, and the spinning and weaving process stretches them. Heat relaxes the tension in the fabric. With the tension relaxed, the fibers pull back to their original length, which shrinks the fabric.
One of the properties that makes spandex so useful is how far it can stretch without losing its original shape. This property, however, does not prevent the fabric from shrinking down.
What Is Spandex Made of?
Spandex is a polyurethane, which is chemically similar to plastic. It is a synthetic polymer, not a naturally occurring fiber. Because it is man-made, it is easy for manufacturers to customize it for their specific needs.
The primary reason for spandex’s invention was to make more comfortable elastic clothing. Stretchiness is the defining characteristic of the fabric. However, that stretch leaves the fabric vulnerable to wearing out quickly.
Pure spandex is rare in the garment industry. Most spandex garments are mixed with other fibers to take advantage of the properties of both fibers. For example, spandex is less sensitive to heat and stretchier than nylon or polyester. Nylon and polyester are both more durable than spandex, so by combining them, manufacturers could make a more comfortable, easy-care, long-lasting fabric than by using any of the three fibers on their own.
Spandex is also expensive to produce. Pure spandex garments are costly, but adding a small amount of spandex to a cheaper fiber makes a much more affordable fabric with much of the stretch benefits of pure spandex.
Does Spandex Shrink When Washed?
Spandex will shrink in the wash if you use hot water. Prolonged exposure to high temperatures can both shrink and melt spandex. While it is more heat resistant than many other synthetic fibers, spandex isn’t as hardy as a natural fiber.
Temperatures of 65°C (150°F) can start the shrinking process for spandex, while temperatures over 177°C (350°F) can melt it. Most washing machines will reach the shrinking temperature for spandex in a typical hot water cycle.
This means you’re unlikely to melt your spandex clothing in the wash. However, the hot water cycle can shrink your spandex. Washing machines aren’t off-limits for spandex, however. You just need to use a cool or cold water cycle.
The motion of a spin washer won’t shrink spandex fabric. It is made to hold its shape well despite significant movement. So as long as the water temperature is well below the shrinking temperature, your washer is safe for your spandex.
Does Spandex Shrink In the Dryer?
The dryer is the place most likely to shrink your spandex. The prolonged high temperature of a heat-dry setting is enough to relax the spandex fibers so that they return to their original size, shrinking the fabric.
Using the dryer also makes the shrinkage more permanent, as it is harder to change the shape of the fabric once it’s dry. Low-heat or no-heat tumble-dry cycles won’t shrink your spandex, though they may stretch it out of shape. To prevent that, put spandex items in a lingerie bag or pillowcase before you dry them.
However, the best way to avoid shrinking spandex is to let it air-dry instead of using a dryer. Since spandex is often used in a blend rather than on its own, the dryer can sometimes shrink the other fibers in a garment more easily than the spandex.
Do Spandex Blends Shrink?
On its own, spandex is fairly resistant to shrinkage. It takes high temperatures to shrink spandex fabric. However, spandex is rarely the only fiber in a garment. It is expensive to make, but a little of it will add enough stretch to other fibers to get a very comfortable fabric.
When thinking about how to avoid shrinking your spandex, you first have to know what else is in the garment. Spandex can shrink up to ten percent, which is significant, but it takes a lot of heat and time to do that. Other fibers can shrink faster and at lower temperatures.
Regardless of the blend, the best way to avoid shrinking your spandex garments is to avoid washing and drying them with high heat.
Spandex/Cotton
Spandex/cotton blends are very common. Cotton is not a stretchy fabric on its own, but it does have many other desirable qualities. It is a strong fiber that’s cheap to manufacture. It takes dye well and versatile, making it useful for a wide variety of garments and textiles.
Adding spandex to a cotton fabric won’t change the sturdiness of the fabric, but it will give it comfortable stretch and give. The cotton helps make the fabric soft, and the spandex helps keep the fabric from stretching out of shape.
Cotton is more prone to shrinkage than spandex. Some cotton gets an anti-shrinking treatment because it is so prone to shrinkage. The more cotton there is in the blend, the easier it will be to shrink the garment.
For example, a 98/2 percent cotton/spandex blend is mostly cotton, so it will shrink more like cotton than spandex. However, a 50/50 blend will be a bit harder to shrink.
Spandex/Polyester
Polyester is a synthetic fabric that manufacturers commonly mix with spandex. It is a stiffer material than spandex, so the spandex fiber gives polyester clothing softness and stretch that 100% polyester doesn’t have.
Polyester is more heat resistant than spandex, so it won’t shrink as easily in the wash as a pure spandex garment. The polyester can help reduce spandex shrinkage when you blend the two, but it won’t prevent it entirely.
The more spandex is in a polyester blend, the more likely you’ll get uneven shrinkage if you wash or dry the garment on high heat. While the polyester fibers will remain largely unchanged, as the spandex fibers relax and shrink, they can warp the shape of the garment.
Spandex/Nylon
Like polyester, nylon is a heat-resistant, shrink-resistant synthetic fabric. It can stand higher washer and dryer cycles than pure spandex can. However, in a blend with spandex, the garment will be more prone to shrinkage.
A good rule of thumb for garment care is to always treat the garment like the most delicate fabric in the blend. So for a spandex/nylon blend, the best way to avoid shrinkage is to treat the item as if it were all spandex.
Low-temperature wash cycles and air drying are the best ways to stop a spandex/nylon blend from shrinking or warping during laundry.
Spandex/Rayon
Rayon, a synthetic material that is supposed to mimic silk, is much more delicate than spandex. It isn’t just susceptible to heat but also moisture. It is far more sensitive to shrinkage and damage than spandex is.
Rayon should not go in the washer or the dryer. The movement, heat, and moisture will damage the fibers and not only cause them to shrink but can wear out the fabric and create holes or tears, too.
While spandex can help rayon garments maintain their shape, it will not make them sturdy enough for machine washing. You should always hand-wash rayon garments or dry clean them.
How to Wash Spandex Without Shrinking It
To avoid shrinking your spandex when you wash it, use a cold or cool water wash cycle, and lay your spandex flat to dry. Avoid hanging wet spandex, as the weight of the moisture, can stretch the fabric out, damaging the elasticity.
Don’t lay your spandex garments out near a heat source, either. Putting them in direct sunlight or near a radiator or other home heating element can also damage them.
Use a mild detergent and make sure to check the fabric content carefully before washing. While it is fine to put spandex in the washing machine, spandex blends may not do well there. If the garment is blended with a more delicate fabric, like viscose, it may not be safe in the washing machine.
If you’re ever in doubt about the fiber content of your garments, hand-washing in cool water with mild detergent and laying flat to dry are the safest ways to launder any delicate garment. These methods minimize the things that contribute most to shrinkage: motion and heat.
How to Shrink Spandex
Over time, spandex can start to lose some of its elasticity. This usually ends up loosening the garment rather than shrinking it. However, you don’t have to toss out your favorite workout leggings just because they’re getting a little baggy.
You can shrink spandex intentionally to get back some of its original fit. Check the garment tag first to see what the fiber content is. If the garment is a blend of spandex and another fiber, you’ll also need to take that fiber’s shrinking properties into account.
Once you know what’s in your garment, shrinking it is as easy as running it through your washer and dryer.
Set your washing machine to the highest heat setting and run the spandex item through a cycle. You don’t need to use detergent; the hot water will start the shrinking process by itself. If your spandex is blended with an easily shrunk, heat-sensitive fabric (like cotton), check the garment after the wash cycle to see if it is the right size, being careful not to stretch the wet material.
If the garment is a blend with a heat-resistant or shrink-resistant fabric (like polyester), you’ll need to run it through a hot dryer as well to shrink it. Put the garment in a pillowcase, mesh laundry bag, or lingerie bag before you put it in the dryer to help it keep its shape as it shrinks.
Use a medium to high temperature setting on the dryer, going by the highest heat the most delicate fabric in the blend can handle. Check the garment every 10-15 minutes until it is the size you want it.
Spandex will usually shrink between 5 and 10 percent. Depending on how much spandex is in a garment, the shrinkage can be slightly tightening or a significant size change.
Conclusion
While spandex itself is resistant to heat, it can still shrink in the washer or the dryer. It’s not common to see 100% spandex clothing, so a large factor in whether or not spandex shrinks is what other fibers are in the garment.
Cool water wash cycles and air-drying are the best ways to avoid shrinking your spandex garments. However, if they start to lose their shape and stretch out, a bit of shrinkage can help bring them back to their original size.
Have you ever accidentally shrunk your spandex garments? Tell us about it in the comments!