Does Polyester Shrink? Textile Experts Explain How to Care for the Fabric

Often, when we go shopping, we look not only at the garment itself, but the tag, too. Knowing the material of your clothing before you buy it prepares you for upkeep and can help you decide which pieces you want to invest in. Generally, it's smart to prioritize natural fibers like cotton and silk, as they’re hypoallergenic, breathable, and more sustainable than synthetic fabrics like polyester. But that’s not to say polyester is without its perks: In fact, you might even say it's the people’s fabric. According to textile specialist and educator Deborah Young (a.k.a. The Textile Expert), polyester is beloved for two main reasons beyond its affordability: It (typically) doesn’t shrink and it’s less likely to wrinkle. But notice how we said typically? According to Young, polyester can sometimes shrink depending on the way it's constructed, making it important to care for it properly so you can keep your favorite pieces looking their best—and luckily, it's fairly easy to do. Keep reading to learn about polyester shrinking and the best ways to avoid it, complete with insights from four fabric experts.

What Is Polyester?

Polyester is a synthetic fabric made in a lab from chemical compounds, and as we mentioned, it's one of the most common materials among affordable and fast fashion brands. “Polyester is a durable, versatile, and quick-drying fabric; however, based on it technically being synthetic cloth, it is not as popular as some of its fabric peers,” says Shauntina Lilly, a fabric expert and the manager of PR, Diversity, & Inclusion at Joann. While polyester is typically less prioritized in comparison to cotton, bamboo, and silk, Lilly says that it’s a great fabric for many types of apparel. Given its durability, it's often possible to keep polyester pieces in your rotation for quite a while with proper care.

Does Polyester Shrink?

Polyester isn't as prone to shrinking as many other types of fabric, but it still might shrink in certain cases. “Whether polyester will shrink depends on the specific construction and manufacturing process of the garment,” says The Laundress brand director Hannah Yokoji. “That being said, polyester is typically durable and can withstand everyday wash and drying methods.”

Tapping into the specific construction, P&G fabric care principal scientist Jennifer Ahoni says that the concern for shrinking mainly occurs when polyester composition isn’t 100 percent. “Garments that are 100 percent polyester have a low likelihood of shrinking,” she says. “If your polyester garment is blended with other fabrics like wool or cotton, or if it is knit vs. woven, it has a higher likelihood of shrinking.” That’s because cotton, rayon, and silk are known to shrink, as are knit fabrics.

Why Does Fabric Shrink?

“Shrinkage is caused when fabric is put under tension during the making and finishing of garments, and when the fabric becomes wet, it wants to relax to its lowest energy state, which is why this process is sometimes referred to as stress relaxation,” Ahoni explains. “Garments made with natural and regenerated fibers, such as cotton and rayon, are more likely to shrink. Knit fabrics such as T-shirts and sweaters will shrink more, but they also have more elasticity so they can regain their shape more easily than a woven fabric such as dress pants.”

How to Prevent Polyester from Shrinking

Since polyester does shrink sometimes (especially with blended fabrics), it’s important to know how to prevent it in order to avoid ruining your favorite garments. Ahead, our fabric experts offer tips on how to tailor your washing and drying cycles to keep your polyester in pristine condition. 

How to Wash It

1. Sort your items: To keep your polyester looking its best, Yokoji recommends first sorting your items by color. When doing so, she suggests checking each tags for any special laundering instructions.
2. Pre-treat any stains: From there, Yokoji says to pre-treat stains with an enzymatic formula (such as The Laundress's Stain Solution. 
3. Use a mesh bag if needed: Before tossing your garments in the wash, consider their design. Anything small, strappy, or delicate should go in a mesh laundry bag to prevent snags and tears, Yokoji says. The Laundress sells a Mesh Bag Bundle with two thin, spacious mesh wash bags, but if you have particularly delicate items, you may want to opt for a thicker bag, like Muchfun's Durable Honeycomb Mesh Laundry Bags.
4. Choose the right cycle: Once your polyester items are ready to wash, add detergent into your machine and select a normal or gentle spin cycle. “Polyester is a synthetic fiber, so to ensure it does not break down from too much heat, opt for cool or warm water when washing,” Yokoji says. Bath & Body Works recently released a delightfully scented Laundry Detergent that's designed to perform in cool water. If you think that only hot water can effectively clean clothes, consider this: “Polyester is comprised of tiny strands of plastic, and when plastic fibers are exposed to extreme heat, shrinkage will occur,” Lilly tells us. “To combat that, wash your polyester pieces in cool water or permanent press if your machine has that option.”
5. Use a good detergent: One more note on washing: Ahoni points out that polyester tends to become dirtier and stinkier—so you may want to opt for a heavy-duty detergent, not to mention one with fragrance. “As synthetic fibers, polyester garments are what we call dirt and odor magnets—they hold on to the body soils that lead to odors more than natural fibers,” she reveals. “Because of this, I’d recommend using a high-quality detergent like Tide Ultra Oxi with Odor Eliminators when washing your polyester garments.”
   

How to Dry It

Just as you shouldn’t wash polyester in hot water, you shouldn’t dry it on high heat, either. “We generally recommend air-drying all synthetic fabrics, including polyester, to help preserve the fabric,” Yokoji says. If you can’t wait for your items to air dry, she says you can place them in the dryer on a low or air tumble setting. “Add wool dryer balls to help reduce static and make drying more efficient,” she suggests. 

Whatever you do, just don’t crank up the heat. “Avoid high heat to prevent damaging or melting polyester fibers,” Ahoni emphasizes.

How to Shrink Polyester on Purpose

If you find a polyester garment you love but wish it was just a smidge smaller, you may be able to shrink it on purpose. “If you’re interested in intentionally shrinking your polyester, place your item in the dryer on high heat—the temperature should be above 100 degrees Fahrenheit,” Lilly says.

Don’t get your hopes too high, though: “Because polyester tends to be very resistant to shrinking, there is no guarantee you can shrink a polyester garment,” Ahoni admits. That said, she says that blended polyester fabrics tend to be easier to shrink. “One way to try shrinking garments is to dry them completely in the dryer,” she adds. “The mechanical action will cause the fibers and yarns to come closer together. This is true for a fabric such as cotton, so a poly-cotton blended item may have a chance of shrinking this way.”

Beyond the dryer, Yokoji says that pre-soaking your polyester in hot water may promote shrinking. “It can be difficult to shrink garments that are already pre-shrunk during the manufacturing process,” she admits. “With that in mind, soaking your item in very hot water for up to an hour, then giving it a spin in a warm dryer may result in shrinkage.” Just keep in mind: If you shrink your polyester garment, there’s a chance that the smaller size won’t fit in the same way, as you can’t control which areas of the garment will shrink.

The Final Takeaway

Polyester is an affordable, durable fabric that's easy to care for overall, which makes it a popular option among more accessible fashion brands. While it’s resistant to shrinking, if it’s blended with natural fibers, heat in the washing and drying process may alter the size and fit. As such, it’s best to wash polyester in cool water and dry it on low heat (or better yet, hang it to dry).