How to Wash Your Hat (Without Ruining It)

A good hat gains character as it ages. Dad hats with muted colors and worn leather straps, vintage ball caps with faded stitching and sun spots from summer days at the park—like other clothing, the imperfections can become part of the charm.

But hats are not like other garments when it comes to washing. Clean a cap wrong and you risk ruining it. Different hats, different ways to destroy them in the name of cleanliness. And when you’re dropping upwards of $50 for a standard-issue MLB ball cap—to say nothing of the three-figure designer models out there—that’s not just unfortunate, it’s costly.

How (and why) hats get ruined

It’s pretty easy to ruin a hat, and a lot of that comes down to structure. The anatomy of a baseball cap varies, with some built to withstand years of wear and others far more fragile than they look. Modern hats often use plastic in the brim, which tends to hold its shape better when exposed to water and heat.

Older hats, like vintage truckers or promotional caps from the ’70s or ’80s, can be a different story entirely. Many used cardboard or paperboard for the brim, both of which can warp, split, swell or permanently lose shape once soaked.

Some corners of the Internet will claim that the top shelf of the dishwasher is the safest place to clean a hat, and that may work for some styles, especially modern hats with plastic brims and stitched logos. But Ezra Watson—a professional hat restorer and the owner of Old Boy Vintage in Bend, Oregon—warns against machine washing as a general rule, especially if you’re not certain about how the hat is constructed.

“People throw hats in the washer or even the dishwasher, which is honestly the worst thing you can do,” he says. “Hats aren’t built to be tossed around like regular clothes. The spinning and tumbling can distort the crown, mess up the brim shape, crack graphics and break down older materials.”

Heat, moisture, and agitation in some combination are usually the culprits, making washing machines and dishwashers a particularly risky play. You might not even notice at first. A hat may seem fine straight out of the laundry, only to dry misshapen hours later.

“If someone already used the machine, the best thing is to reshape it while it’s still slightly damp,” advises Watson. “Don’t let it dry all twisted… gently bend the brim back into shape by hand and let it dry on something rounded so the crown keeps its form. Sometimes you can save the fit pretty well if you catch it early enough. Once a brim fully dries warped, though, it gets a lot harder.”

The proper way to clean and dry a hat

Ezra’s principle of “less is more” applies to all hats, regardless of material. So first, inspect. What is the hat made of? How and where is it dirty? Could a spot wash take care of it? If so, it’s a safe place to start.

“I always say start as light as possible, spot clean first, cold water only and use something mild,” he says. “No bleach, no heavy chemicals. A lot of times people go too hard scrubbing and end up damaging the fabric or cracking the print.”

Another crucial step of the process where hats commonly get destroyed is drying and reshaping. Ezra advises doing the reshaping by hand immediately after cleaning and only ever letting hats air dry. Do not use the laundry or toss it in the sun and expect to reform it to your head after it’s dry. One way to help a wet hat retain proper form is to let it dry over something round like a bowl or ball.

For delicate wool caps or older vintage hats, some people turn to dry cleaners. Watson says that can work, but selectively. “I wouldn’t trust most dry cleaners with older vintage hats unless they really know what they’re doing,” he says. “A lot of cleaners are great with garments, but hats are kind of their own thing because of the structure.”

Use a toothbrush to scrub the sweatband

One common way caps get dirty is when sweat soaks into the inner band. And on some people’s skin, that buildup plus the moisture, heat and friction of the hat rubbing, can cause acne breakouts on the forehead.

Luckily, sweat stains that haven’t fully set on the band are relatively easily combated. “We don’t use anything crazy gear-wise,” explains Watson. “Just soft brushes, microfiber cloth, mild detergent and cold water. Sometimes a soft toothbrush honestly works best for getting into the sweatband and around the seams. It’s more about control than using strong products.”

Dilute a few drops of soap in warm water, and using a soft toothbrush, gently wipe the affected area. A bit of baking soda may help with some stains.

What cleaning won’t fix—and when to stop trying

Some stains can’t be cleaned, no matter how precious the item they’re on. “Heavier sweat stains can improve but not always fully go away, especially if they’ve been sitting for years,” says Watson. “Stuff like sun fading, deep yellowing or foam breakdown is pretty much permanent. Cleaning can make a hat better, but it’s not going to make it brand new again.”

A stain doesn’t need to mean permanent retirement, though. Take it from the owner of a vintage shop: some evidence of age is cool. When hats come into Watson’s store, each is assessed and addressed individually. Some are cleaned based on their needs. Some sent to the thrift. Others are sold as is.

“If a hat is old or valuable, honestly less is more. I wouldn’t fully wash it unless you really have to,” he says. “A lot of the wear is part of what makes it cool anyway, so you don’t want to overdo it and lose that.”

This article originally appeared in GQ.com.