When shopping for swimwear, most of us focus on style, fit, and price. But the fabric your bikini is made from significantly impacts how it performs, how long it lasts, and how comfortable it feels. Understanding swimwear fabrics helps you make smarter choices and get better value from your purchases.
Swimwear fabrics have evolved tremendously from the wool bathing suits of the early 20th century. Today's materials are engineered for specific performance characteristics—stretch, recovery, chlorine resistance, UV protection, and quick-drying properties. This guide demystifies swimwear fabrics so you can choose materials that match your needs.
The best swimwear fabric depends on how you'll use it. Frequent pool swimmers need chlorine-resistant materials, ocean swimmers benefit from quick-dry fabrics, and fashion-focused beach loungers might prioritise luxurious textures over performance features.
The Core Fabrics
Nylon (Polyamide)
Nylon is the most common base fabric for swimwear. Developed in the 1930s, it revolutionised swimwear with its lightweight, quick-drying, and durable properties.
Advantages:
- Exceptionally soft and comfortable against skin
- Lightweight and quick-drying
- Strong and abrasion-resistant
- Excellent colour retention
- Smooth, flattering drape
Disadvantages:
- Less resistant to chlorine than polyester
- Can lose shape over time with heavy chlorine exposure
- Typically more expensive than polyester
Best for: Fashion swimwear, beach use, occasional swimming
Polyester
Polyester is the workhorse of performance swimwear. It's particularly valued for competitive and regular training swimwear due to its exceptional durability.
Advantages:
- Highly resistant to chlorine degradation
- Excellent shape retention
- Very durable—lasts longer than nylon in harsh conditions
- Resistant to UV fading
- Generally more affordable
Disadvantages:
- Less soft than nylon—can feel slightly coarser
- Heavier when wet
- Less luxurious feel
Best for: Regular pool swimmers, training swimwear, longevity-focused purchases
Nylon vs. Polyester: Quick Comparison
Choose nylon for comfort and aesthetics; choose polyester for durability and chlorine resistance. Many quality swimwear brands blend both to capture the benefits of each.
Elastane (Spandex/Lycra)
Elastane is the stretch component in virtually all modern swimwear. You'll never find a swimsuit made entirely of elastane—it's always blended with nylon or polyester to provide stretch and recovery.
What it does:
- Provides the stretch that allows swimwear to fit closely
- Enables shape recovery after stretching
- Creates the "second skin" fit of quality swimwear
- Allows freedom of movement in the water
Common blend ratios:
- 80% nylon/20% elastane: Standard fashion swimwear
- 78% nylon/22% elastane: Extra stretch and compression
- 50% polyester/50% PBT: High-performance, maximum durability
Elastane is the most vulnerable component of swimwear. Chlorine, heat, sunscreen, and body oils all attack elastane fibres, causing the dreaded saggy, stretched-out fit over time.
Specialty Fabrics
PBT (Polybutylene Terephthalate)
PBT is an advanced polyester variant used in high-performance swimwear, particularly competitive suits.
- Exceptional chlorine resistance—far superior to standard fabrics
- Excellent shape retention even after intensive use
- Quick-drying properties
- Commonly blended with polyester for training swimwear
If you swim laps several times a week, look for swimwear containing PBT. The investment in this superior fabric pays off in dramatically extended lifespan.
Neoprene
Neoprene is the thick, spongy material used in wetsuits. In fashion swimwear, thin neoprene creates structured, sculptural shapes and provides buoyancy.
- Provides structure and body to swimwear
- Thick enough to eliminate the need for lining
- Creates distinctive textured appearance
- Offers some insulation for cooler water
- Quick-drying surface
Neoprene swimwear is more fashion-forward than functional. It's not ideal for serious swimming but makes a statement at the beach or pool party.
Ribbed and Textured Fabrics
Ribbed fabrics add visual interest and can provide a more forgiving fit:
- The textured surface can hide minor imperfections
- Often provides more coverage due to fabric thickness
- Creates interesting visual and tactile appeal
- May take longer to dry than smooth fabrics
Performance Features
Chlorine Resistance
Chlorine is one of the biggest enemies of swimwear. It attacks elastane fibres, causing loss of stretch and shape. Chlorine-resistant swimwear uses special fabric treatments or inherently resistant materials like PBT.
Look for labels mentioning:
- Chlorine resistant
- Chlorine proof
- Xtra Life Lycra (treated elastane with extended chlorine resistance)
- High PBT content
UPF (Ultraviolet Protection Factor)
UPF ratings indicate how much UV radiation fabric blocks. Given Australia's intense sun, this feature deserves attention:
- UPF 15-24: Good protection (blocks 93.3-95.9% UV)
- UPF 25-39: Very good protection (blocks 96-97.4% UV)
- UPF 40-50+: Excellent protection (blocks 97.5%+ UV)
Darker colours and tighter weaves naturally provide higher UV protection, even without specific UPF treatment.
UPF Reminder
UPF protection applies only to covered skin. You still need sunscreen on exposed areas, and fabric protection decreases when stretched thin or wet.
Quick-Dry Technology
Quick-dry fabrics use either fibre structure or chemical treatments to wick moisture away from the surface, allowing faster evaporation. Benefits include:
- More comfortable after leaving the water
- Reduced chafing from wet fabric
- Convenient for multi-activity days
- Helps prevent mildew during travel
Compression Fabrics
Some swimwear uses compression technology to smooth and shape the body:
- Higher elastane content creates compression effect
- Can provide tummy control and shaping
- Popular in one-pieces and high-waisted styles
- Should feel snug but not restrictive
Sustainable Fabric Options
Environmental awareness has driven innovation in sustainable swimwear fabrics:
ECONYL
Regenerated nylon made from ocean waste, fishing nets, and industrial plastic. Performs identically to virgin nylon with a significantly reduced environmental footprint.
Recycled Polyester (rPET)
Made from recycled plastic bottles. Diverts plastic from landfills while creating durable swimwear fabric.
REPREVE
A branded recycled fibre with traceability certification. Each REPREVE product can be traced back to the plastic bottles it came from.
For more on sustainable options, see our sustainable swimwear guide.
Reading Swimwear Labels
Understanding care labels helps you choose wisely and care for your swimwear properly:
- Fabric composition: Look for the percentage of each material
- Higher elastane (20%+): More stretch and compression
- Polyester-dominant: Better for pool use
- Nylon-dominant: Softer feel, better for fashion/beach
- Special features: Chlorine resistance, UPF ratings
Matching Fabric to Use
- Daily lap swimming: Polyester/PBT blend, chlorine-resistant
- Occasional pool use: Nylon/elastane with chlorine resistance
- Ocean swimming: Quick-dry, good shape retention
- Beach lounging: Fashion fabrics, comfort priority
- Water sports: Quick-dry, secure fit, UPF protection
- Travel: Quick-dry, wrinkle-resistant
Understanding fabrics empowers you to make informed choices, get better performance from your swimwear, and extend the life of pieces you love. The best bikini isn't just one that looks good—it's one made from materials suited to how you'll actually use it.