What sets a quality swimsuit apart is not its colour or print, but five construction details: fabric composition, lining, seams, hardware and fit features. These details determine whether the swimsuit keeps its shape after ten swims or starts to stretch after the very first. Much of the advice online suggests choosing a swimsuit by body type, but even the most flattering silhouette won’t help if the fabric is too thin, the lining only partial and the seams coming apart. This guide will help you assess quality before your first swim.
Key takeaways
- Fabric composition: Look for polyamide or polyester with 15–20% elastane, as this blend helps the garment keep its shape and resist stretching even after many swims.
- Double lining: This is one of the clearest signs of quality. It keeps the fabric from becoming see-through when wet, feels softer against the skin and makes the swimsuit last longer.
- The right seams: Flat or zigzag seams sit close to the skin, do not chafe and show that the garment has been made specifically for swimming.
- Sturdy details: Metal clasps and strap adjusters are far more durable than plastic ones, as they hold up better against salt and chlorine.
- Comfortable fit: Adjustable straps and removable cups make it easy to adapt the swimsuit to your figure so it fits perfectly.
Swimsuit quality compared: what the details reveal
| Quality detail | Sign of quality | Sign of low quality |
|---|---|---|
| Fabric composition | Polyamide or polyester with 15–20% elastane | Less than 10% elastane or an unclear composition on the label |
| Lining | Full two-layer lining throughout the garment | Partial lining only at the front or in the gusset |
| Seams | Zigzag or flatlock seams that lie flat against the skin | Standard overlock seams with a raised edge |
| Hardware | Metal adjusters and sliders, corrosion-resistant | Plastic hardware, prone to breaking and corroding |
| Fit | Adjustable straps, removable cups, high-cut legs | Fixed size with no adjustment options |
What makes a quality swimsuit stand out?
A quality swimsuit is made from materials that easily withstand sunlight, salt, chlorine and beach cosmetics. Even after many swims, it does not stretch out or fade.
Why is fabric composition the most important quality indicator?
Swimsuit fabric needs to stretch evenly, keep its original shape after swimming and resist salt, chlorine, sunlight and sunscreen stains. That is why the composition label is the first thing worth checking.
Fabric fibres:
- Polyamide (nylon): A soft, smooth and supple fibre. This is the best choice for everyday beach relaxation.
- Polyester: More resistant to chlorine and UV rays.
- Natural fibres (cotton, linen): Completely unsuitable for swimming. They absorb moisture, dry slowly, stretch under the weight of water and are quickly damaged by the sun.
Ideal proportions:
- Around 20% elastane (the rest polyamide or polyester): this blend usually offers a good balance of stretch, comfort and durability.
- Less than 10% elastane: the fabric will be too stiff and won’t hug the body well.
- More than 25% elastane: the garment will feel too tight, and the fabric will wear out faster from chlorine.
Fabric properties:
- Quick drying: Quality fabric does not hold moisture, so the swimsuit does not get heavy or stretch out.
- Clear label: If the manufacturer lists the exact percentage composition, it shows attention to quality. If the information is vague, it is worth looking for another option.
What does the inside of a swimsuit tell you?
Turn a swimsuit inside out and you can immediately assess the two most important signs of quality: the lining and the seams. These details, hidden from the outside, decide whether the garment will last several seasons or lose its shape after a few swims.
Why lining matters:
- Full lining: In a quality garment, the lining covers the entire inside, not just the front or the gusset. This keeps the fabric from becoming see-through when wet, makes it pleasant on the skin and helps the garment keep its shape.
- Light shades: For white and light-coloured styles, a double layer is essential so the swimsuit does not become see-through when wet.
Seam construction:
- Specialist seams: Swimwear uses flat or zigzag seams. They lie close to the skin, do not chafe during movement and stretch with the fabric. For example, Aruelle’s one-piece Belle style has internal zigzag seams that add flexibility while the outside stays completely smooth.
- Conventional seams: Standard raised seams can chafe the skin during more active movement or longer periods in the water.
Quick check:
Gently pull a seam sideways. A quality seam will stretch slightly and immediately return to its original position, with no gaps left between the stitches. If the seam opens up straight away or the stitches look sparse, the garment will not withstand frequent swimming.
Hardware and fit: details worth checking before you buy
The comfort and durability of a quality swimsuit often come down to details that seem small at first glance: metal elements and fit options.
Metal details:
- Resistance to the elements: Quality swimsuits use metal clasps, rings and strap adjusters. They hold up better against chlorine and salt, while plastic parts break more easily and fade in the sun.
- Finish quality: Cleanly polished metal has no sharp edges, so it does not rub the skin and looks neat.
Fit for your figure:
- Adjustable straps and cups: These make it easy to adapt the garment to your body’s lines. Removable cups give you a choice between a firmer structure and a more natural look.
- Back construction and shaping effect: Internal mesh linings gently shape the tummy area, while crossover straps or back fastenings keep a deeper-cut swimsuit from slipping.
- Brand example: Aruelle’s one-piece Mona style has all of these elements: metal strap adjusters, removable cups and an internal mesh lining for light support.
What can’t even a quality swimsuit withstand?
Even the highest fabric quality cannot protect against certain environmental factors. Elastane, which gives the garment its stretch, is the most sensitive component: it is gradually broken down by chlorine, salt, sunscreen and high temperatures.
Choosing the fabric type for the setting:
- Polyamide: Soft and very comfortable on the skin, so it is ideal for seaside holidays, but more sensitive to long-term chlorine exposure.
- Polyester: Slightly rougher, but far better at withstanding chlorinated tap and pool water, so it is better suited to regular training.
What damages the fabric most?
- Leaving it in a bag: Keeping a wet swimsuit wrapped in a towel or in a bag speeds up fibre breakdown, and pressure deforms the cups.
- Rough surfaces: Concrete pool edges, rocks or sauna benches quickly snag and damage the outer layer of fabric.
- Heat and tumble dryers: Drying in direct sunlight or in a tumble dryer irreversibly breaks down elastane.
Basic care rules:
- After each use, rinse the swimsuit in cool water to remove salt, chlorine and sunscreen residue.
- Hand wash only and leave to dry in the shade.
Proper care does not change the fabric’s properties, but it helps a quality swimsuit last several times longer.
Frequently asked questions
What is the best fabric for a swimsuit?
The best choice depends on how you use it. Polyamide with 15–20% elastane is softer, hugs the skin more gently and is better suited to beach leisure or seaside holidays. Polyester with elastane will better withstand regular chlorine exposure in the pool, and its colours fade more slowly. In both cases, the elastane percentage determines the swimsuit’s stretch, its shape and how long it will look new.
Does a swimsuit lining really matter?
Yes. A full lining ensures opacity (especially important for light colours), adds a layer of durability and feels softer against the skin. A partial lining that only covers the gusset is a sign of cost-cutting, not a design choice.
How do I care for a swimsuit so it lasts longer?
After each swim, rinse the swimsuit in cold or lukewarm water to remove chlorine, salt and sunscreen residue. Hand wash only, without bleach or harsh detergents. Hang to dry in the shade, away from direct sunlight. Do not roll a damp swimsuit up in a towel and never use a tumble dryer. These rules protect the elastane fibres from breaking down too quickly.
What is the difference between flatlock and overlock seams in a swimsuit?
Flatlock and zigzag seams lie flat against the skin and stretch with the fabric. Standard overlock seams create a raised edge that rubs against the skin and can split under tension. In swimwear, flat seams are a sign of both comfort and durability.
Is metal hardware better than plastic?
Quality metal hardware (adjusters, sliders, clasps) is more resistant to corrosion and mechanical wear. Plastic hardware can break, fade in the sun and cause discomfort when damaged. Metal elements also indicate the overall quality level of the product.
