Swimsuit Care: How to Survive the Chlorine, the Salt, and the Sunscreen Without the Sag

A swimsuit is the garment most people ruin by the end of the first summer, because the three things it is exposed to — the chlorine, the salt, and the sunscreen — are the three things that degrade the elastane (the spandex) that gives the suit its stretch and its shape, and the suit that is not rinsed after the wear and is thrown in the hamper for a hot wash is the suit that comes out saggy, faded, and stretched out by the fourth wear. The elastane is the fiber that fails first, and it fails faster in the chlorine and the salt and the heat of the wash than the nylon or the polyester it is blended with, and the loss of the elastane is the loss of the fit — the suit that no longer snaps back, that bags at the seat, that stretches at the straps. The right protocol is the one that rinses the chlorine and the salt off the suit the moment it comes off, that hand-washes the sunscreen and the body oil gently, and that dries the suit out of the sun, and the suit that gets it lasts a season or two; the one that does not is the suit that sags by the fourth pool day.

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Why a Swimsuit Is a Spandex Problem

A swimsuit is a blend — most commonly a nylon-spandex or a polyester-spandex, where the nylon or the polyester is the durable fiber and the spandex (the elastane, the Lycra) is the 15 to 20 percent that gives the suit its stretch and its recovery. The spandex is the fiber that degrades in the chlorine, the salt, and the heat, and the loss of the spandex is the loss of the suit's shape — the sag, the bag, the stretch that does not snap back. The chlorine is the chemical that breaks the elastane's polymer chain (it is, after all, the chemical that degrades the elastane in the pool, which is why the suit wears out faster in a chlorinated pool than in a freshwater lake); the salt is the abrasive and the dehydrator that stiffens and then brittles the fiber; the sunscreen is the oil that bonds to the fiber and that the body's heat bakes in, and the oil-stained suit is the suit with the yellowed and the weakened elastane. The protocol that extends the suit's life rinses all three off the suit the moment it comes off.

The Post-Swim Rinse — the Non-Negotiable

The single step that extends a swimsuit's life more than any other is the post-swim rinse, and it is the one most people skip because the suit goes in the bag and the hamper. The protocol: the moment the suit comes off, rinse it under cold, running water (or in a sink of cold water) to flush the chlorine and the salt out of the fiber, and gently squeeze (never wring) the water through the fabric. The rinse that happens at the pool or the beach, within minutes of the swim, removes the chlorine and the salt before they have time to degrade the elastane; the suit that goes in the bag and is rinsed at the end of the week is the suit that has been marinating in the chlorine and the salt for five days, and the damage is done. The post-swim rinse is the two-minute habit that saves the suit.

The Hand-Wash — Gentle and Cool

After the rinse, the remaining soil — the sunscreen, the body oil, the sand — is lifted with a gentle hand-wash, and the protocol is the one that respects the spandex. The protocol: a basin or a sink of cool water (never hot, which degrades the elastane) with a drop or two of a gentle, pH-neutral detergent (a mild liquid detergent or a hand-wash soap; never a standard laundry detergent, which is too harsh and can strip the suit's color and its elastic). Swish the suit through the water gently, squeeze the suds through the fabric (never wring, never twist, which stretches the elastane out of shape), and let it soak 10 to 15 minutes for the sunscreen and the oil. Rinse in cool water until the suds are gone, with a final rinse that has a teaspoon of white vinegar — the acid neutralizes the chlorine residue and the alkaline detergent, and it restores the fiber the way a hair conditioner restores the hair.

The Sunscreen Stain

The sunscreen is the oil that yellows the suit and that the body's heat bakes in, and it is the stain that the cool wash alone may not lift. The protocol for a visible sunscreen stain: pre-treat the stain with a drop of the gentle detergent or a degreasing spot treatment, worked in gently by hand, and let it sit 10 to 15 minutes before the wash. The oil that is pre-treated lifts in the cool wash; the oil that goes in the hamper untreated and hot is the oil that sets and yellows the suit. Never use a stain remover with the chlorine bleach on a swimsuit — the chlorine degrades the elastane and the color, and it is the fastest way to ruin the suit after the pool itself.

The Dry — Out of the Sun

The dry is the step that most people get wrong with the sun, and the sun is the ultraviolet that fades the color and degrades the elastane — the suit that dries in the direct sun is the suit that fades and sags faster. The protocol: air-dry the suit flat, in the shade or the indoors, away from the direct sun and the heat. Never the dryer (the heat degrades the elastane and shrinks the suit), never the sun (the UV fades and degrades), and never wring the suit to dry it (the wring stretches the elastane out of shape). Roll the suit in a clean, dry towel to extract the excess water, then lay it flat on a fresh towel or a drying rack, in the shade, and let it dry fully before the next wear. The suit that dries flat in the shade keeps the shape and the color; the one that dries in the sun and the heat is the suit that sags and fades.

The Storage and the Rotation

The swimsuit that is stored damp is the swimsuit that mildews and that grows the bacteria in the elastic, and the suit that is stored stretched is the suit that loses the shape. The protocol: store the suit fully dry, flat or loosely folded, in a dry, cool drawer — never in a plastic bag, never in the heat of the car, never compressed. Rotate two or three suits through the season so each suit has a day to dry and recover between wears — the suit that is worn daily, in the chlorine, does not have the time to recover the elastane, and it is the suit that sags first. The rotation is the simple discipline that doubles the life of each suit in the rotation.

Frequently Asked Questions

How do I keep a swimsuit from sagging?

Rinse the chlorine and the salt off the suit the moment it comes off — the post-swim cold rinse is the single step that extends the suit's life. Hand-wash cool and gentle, and air-dry flat in the shade, never the dryer, never the sun.

Can I machine-wash a swimsuit?

On the gentlest, coldest cycle, in a mesh bag, with a gentle detergent — and never with the chlorine bleach, never with the fabric softener, never in the dryer. Hand-washing is the gentler choice and the one that extends the suit's life the most.

Why does my swimsuit fade and yellow?

The sun (the UV fades the color) and the sunscreen (the oil yellows and bakes in). Air-dry in the shade, pre-treat the sunscreen stains, and never the chlorine bleach, which degrades the color and the elastane.

How do I get sunscreen out of a swimsuit?

Pre-treat the oil stain with a drop of gentle detergent or a degreasing spot treatment, let it sit 10 to 15 minutes, then hand-wash in cool water. Never a chlorine stain remover, which ruins the suit.

How should I store a swimsuit?

Fully dry, flat or loosely folded, in a dry, cool drawer. Never damp, never in a plastic bag, never in the heat of the car. Rotate two or three suits so each has a day to recover between wears.

The Bottom Line on Swimsuits

Rinse after every wear, hand-wash cool and gentle, air-dry flat in the shade, never the dryer, never the sun, and rotate the suits. That is the care that keeps the stretch and the shape for the season — and for delicates you would rather hand off, our Drop Off Wash & Fold teams across Greensboro, Winston-Salem, and Burlington handle delicates.