How to Wash Swimwear Without Stretching the Fabric
By Home | Published: 2026-10-13
Category: Tips & Care
Swimwear stretches out when it's washed wrong. Follow this simple hand-wash routine to keep your tankini and briefs fitting like new, without harsh heat or twisting.
Quick answer
Hand wash swimwear in cool water with a little mild detergent, then gently squeeze the water out and lay it flat to dry away from direct sun. The two biggest causes of stretched swimwear are hot water and wringing or twisting the fabric. Skip the washing machine and dryer entirely.
Why heat and twisting stretch swimwear
Swim fabric relies on elastic fibres to hold its shape. Hot water and high heat relax those fibres, and once they lose tension they don't spring back. Twisting or wringing does the same damage mechanically, pulling the fabric out of shape while it's wet and vulnerable.
Chlorine and salt aren't kind either. They break down elasticity over time, so rinsing soon after every swim matters as much as how you wash. A gentle routine done consistently will keep a swimsuit fitting well far longer than an occasional deep clean.
What you need before you start
You don't need special equipment. A clean sink or basin, cool water, and a small amount of mild liquid detergent or gentle soap will do. Avoid anything labelled as a stain remover, bleach, or fabric softener, because those can damage swim fabric and dull colours.
If you're washing more than one piece, keep lights and darks separate for the first few washes in case of colour transfer. Check the care label on your swimwear too, since some pieces have specific instructions that take priority over any general routine.
Drying without losing shape
Lay swimwear flat on a clean towel, reshape it with your hands, and let it air dry out of direct sunlight. If you need to speed things up, roll the item in a dry towel and press gently to absorb water, then lay it flat again.
Never hang a wet swimsuit by its straps or leave it draped over a radiator or heater. The weight of the water pulls the fabric down while it dries, and heat does the same fibre damage as a hot wash. Both are common reasons a swimsuit starts to sag after a few wears.
Your step-by-step hand-wash routine
- Rinse straight after wearing: Fill a basin with cool water and swish your swimwear through it for about 30 seconds to remove chlorine, salt, and sunscreen. If you can't rinse immediately, do it as soon as you're home rather than leaving it in a bag. Checkpoint: the water should run clear before you move on.
- Wash with a small amount of mild detergent: Add a drop of mild liquid detergent to cool water, submerge the swimwear, and gently squeeze the suds through the fabric with your hands. Don't scrub, and don't leave it to soak for more than 10 to 15 minutes. Common mistake: using hot water or too much detergent, both of which are hard on elastic fibres.
- Rinse until the water runs clear: Drain the basin and refill with cool water, then press the swimwear gently under the surface. Repeat until no suds remain. Detergent left in the fabric can attract dirt and irritate skin. Checkpoint: squeeze a section of fabric and check that the water coming out is clear, not soapy.
- Remove water without wringing: Cup the swimwear in both hands and press the water out, or lay it on a clean towel and roll the towel up gently. Never twist, wring, or stretch the fabric while it's wet. Common mistake: wringing is the fastest way to stretch a swimsuit out of shape.
- Dry flat, away from heat and sun: Reshape the swimwear by hand and lay it flat on a dry towel or drying rack. Keep it out of direct sunlight and away from radiators, heaters, and tumble dryers. Checkpoint: the piece should be fully dry before it goes back in a drawer, so it doesn't stay damp and musty.
How this applies to our swim pieces
- Swim Flexi-Size Tankini - Blue Rainbow ***: The Swim Flexi-Size Tankini has a drawstring tie at the front so you can change the look. A drawstring means extra fabric and a knot to look after in the wash. Tie it loosely before washing so it doesn't pull on the front panel, and check the knot is undone before drying so the fabric dries evenly.
