Quick answer

Rinse your swim briefs or trunks in cool water immediately after every swim, then hand wash with a mild detergent. Never use hot water, bleach, or a machine dryer. Lay flat or hang to dry in the shade. This routine removes chlorine and salt, protects padded panels and smart cups, and prevents color fading.

Why swim briefs and trunks need a different wash routine

Chlorine, saltwater, sunscreen, and body oils break down swimwear fabrics and elastic faster than normal underwear. Padded swimwear and styles with a smart cup have extra layers and bonding that can warp or lose shape in a hot dryer. A dedicated wash routine keeps the fit, color, and padding intact.

Gather the right supplies before you start

You only need a few things: a basin or sink, cool water, and a mild liquid detergent. Avoid woolite or harsh detergents with bleach or fabric softener. For travel, a gentle swimsuit cleaner works, but baby shampoo is a safe backup. Never use a washing machine unless the care label explicitly allows it.

Step-by-step: How to wash swim briefs and trunks

Follow these steps in order. Each step includes a common mistake to avoid.

Your 5-step swimwear wash routine

  1. Rinse immediately after swimming: As soon as you leave the pool or ocean, rinse your swim briefs or trunks in cool running water. This removes most chlorine, salt, and sunscreen before they set into the fabric. Checkpoint: If you can't rinse right away, at least soak them in cool water as soon as possible.
  2. Hand wash with mild detergent: Fill a sink with cool water and add a small amount of mild liquid detergent. Gently squeeze the suds through the fabric for 1–2 minutes. Pay attention to the padded areas and waistband. Common mistake: Using hot water or harsh detergent, which can break down elastic and fade colors.
  3. Rinse thoroughly in cool water: Drain the soapy water and rinse with cool water until no suds remain. Leftover detergent can attract dirt and irritate skin. Checkpoint: The water should run clear with no slippery feel.
  4. Remove excess water without wringing: Lay the swimwear flat on a clean towel and roll the towel up to press out water. Never twist or wring, especially on padded styles, as this can distort the padding and smart cup. Common mistake: Wringing out swimwear like a towel, which stretches the fabric and damages padding.
  5. Air dry in the shade: Lay flat or hang to dry away from direct sunlight and heat sources. Sun and high heat cause color fading and weaken elastic. Make sure the item is completely dry before storing. Never use a machine dryer. Even low heat can shrink or warp swimwear.

Product care notes

  • H2O Padded + Package Swim Brief: H2O Padded + Package Swim Brief features Smart Cup Tech and is part of the H2O collection. The smart cup and padding need gentle hand washing to keep their shape and avoid crushing.
  • Basic Padded Boxer Trunk: Basic Padded Boxer Trunk has PADDED Tech for more gluteal volume and a short inseam. The padding can compress or shift if machine washed or dried on high heat, so hand washing is safest.
  • WAVEFORM PRIDE Padded Brief + Smart Package Cup: WAVEFORM PRIDE Padded Brief + Smart Package Cup combines padding with a smart cup and comes in vibrant colors. Vibrant colors fade quickly in chlorine or direct sun, so rinse and dry in shade to preserve the look.