How to choose a fabric for swimwear (a complete guide)

Besides looking great, you also need your swimsuit to perform. We’ll show you how to choose fabrics that stand up to water, sun, and chlorine. The right materials protect your skin, maintain shape, and last for more than a season, while the wrong ones stretch out, break down, and leave your skin vulnerable to UV rays.

Quick links:

Synthetic fabrics

Natural and alternative fabrics

Recycled fabrics

UPF-rated fabrics

Fabric performance features

How to choose the right swimsuit fabric

How to care for your swimsuit

Let's dive into swimwear fabrics so you can pick a swimsuit that’s as functional as it is stylish.

Your Swimwear fabric choices

Swimwear fabrics combine natural or synthetic fibers in specific weaves to create a material that performs in water. Each type offers different levels of protection, durability, and comfort.

Synthetic fabrics

Synthetic materials dominate swimwear because of their unique molecular structure. These manufactured fibers repel water, resist chemicals, and stretch with your body. Their tight weave blocks UV rays and maintains shape after repeated use in pools and oceans.

Nylon (Polyamide)

Nylon fabric dominates swimming apparel because of its exceptional properties. This lightweight synthetic fiber dries fast and resists abrasion from sand and pool surfaces. Its natural stretch gives swimmers a full range of motion without restricting movement.

Most swimwear blends nylon with 10–20% spandex for optimal stretch and recovery. Pure nylon absorbs more water than other synthetics, so manufacturers often add polyester to reduce water retention.

Plain nylon offers minimal UV protection on its own: about UPF 5. Some manufacturers use a tight weave construction and special UV-absorbing additives to boost protection. When shopping for nylon swimwear, look for UPF 50+ fabrics. They block 98% of UV rays through added treatments and fabric engineering.

Polyester

Polyester is a durable, affordable synthetic fiber that repels water. This fabric resists fading from chlorine and saltwater, retains its shape through multiple swims, and dries rapidly after use.

Manufacturers mix polyester with 15–25% spandex to add stretch without compromising durability. The combination creates swimsuits that maintain their fit over time. Pure polyester resists moisture absorption better than nylon, which keeps swimsuits lighter in the water.

The molecular structure of polyester fabric naturally blocks more UV radiation than nylon, starting at UPF 15. Special treatments and tight weave patterns increase protection up to UPF 50+, blocking over 98% of harmful rays. Colored polyester offers excellent UV protection through light-absorbing dyes.

Spandex/Elastane/Lycra

Spandex, elastane, and Lycra® represent the same stretchy fiber under different names. If you live in North America, you’re probably familiar with spandex. If you’re from Europe, elastane is the generic term. Lycra is a trademarked blend of spandex/elastane. These materials enhance swimsuit stretch and recovery. The fibers spring back to their original shape after stretching up to 5–8 times its length. A mere 15–25% spandex content creates swimwear that moves with your body and returns to form.

Different water activities demand specific spandex ratios. Racing suits contain 15–20% for compression and drag reduction. Recreational swimwear uses 20–25% for comfort and flexibility. Too much spandex reduces durability and UV protection.

Chlorine, heat, and body oils break down spandex over time. Saltwater accelerates deterioration and causes swimsuits to lose their bounce-back ability. UV rays also degrade the fibers, which leads to sagging and exposed threads. The delicacy of spandex is why it is blended with other swimwear fibers. Pure spandex swimwear lacks durability and becomes transparent when wet. 

High-quality spandex maintains opacity in water and resists temperature changes. It also offers superior recovery and longevity but costs more. You typically don’t need a swimsuit with a high spandex blend (over 25%).

PBT (polybutylene terephthalate)

PBT has superior chlorine resistance than standard polyester and nylon. This engineered fiber maintains its strength and shape even after hundreds of hours in treated pool water. The molecular structure repels chlorine molecules, preventing the degradation common in other synthetics.

Professional swimmers and athletes favor PBT for its performance qualities. The fiber retains less water than other synthetics and reduces drag during competitive swimming. Its natural stretch provides muscle compression without spandex content, and the material instantly springs back to shape.

PBT resists pilling, snagging, and abrasion from pool surfaces. The fiber withstands repeated exposure to sunscreen, bodily fluids, and saltwater without breaking down. Its color retention surpasses standard polyester to keep swimsuits vibrant through multiple seasons of heavy use.

The fiber's rapid drying time prevents bacterial growth between swims. Competition swimwear often incorporates PBT panels in high-stress areas for extended garment life. Its resistance to oils prevents weakening at seams and stress points where body oils typically accumulate. If you participate in competitive watersports or spend a lot of time in chlorinated pools, look for swimwear made of PBT.

Natural and alternative fabrics

Natural and alternative fabrics let you be eco-friendly with your swimwear. Though less common than synthetics, these sustainable options offer unique properties for specific swimming needs.

Cotton blends

Cotton blends cost less than technical swimwear fabrics and provide natural fiber content that creates soft, breathable garments. While a cotton/polyester mix absorbs less water than pure cotton, it still takes longer to dry than pure synthetics. These properties make cotton blends more suitable for cover-ups and beach accessories rather than swimsuits themselves.

There are several practical limitations to using cotton blends in swimwear.

• The material stretches out when wet and shrinks during washing, making it problematic for fitted swimwear.

• The loose weave structure allows UV rays to penetrate, providing minimal sun protection.

• Pool chemicals rapidly degrade the cotton fibers.

• Saltwater can stiffen and discolor the material.

Cotton blend swimwear is also hard to maintain. Bacteria thrive in damp cotton fibers, and while manufacturers sometimes add antimicrobial treatments, these wash out over time. The material also tends to hold onto sand particles, requiring extra rinses after beach use.

Cotton blends are great for beach towels and casual swim shorts due to their softness and affordability, but you should skip them for your swimwear.

Hemp

Hemp is a highly sustainable fabric. The plant grows fast without pesticides and uses minimal water. Its natural antimicrobial properties reduce the need for chemical treatments.

While stronger than cotton, it still breaks down under UV rays, dries slower than synthetics, and becomes stiff after saltwater exposure. Pure hemp also lacks elasticity.

Hemp swimwear usually uses a sub-50% blend combined with cotton and spandex to provide stretch and recovery. It usually undergoes a softening treatment to minimize rigidity. One advantage hemp has over cotton is that it is antimicrobial.

Since hemp is an emerging eco-friendly fabric option, you'll have to do some trial and error to find a suit that meets your needs. Current production methods also limit color options and increase costs compared to synthetic swimsuits, but you will be shedding less microplastic and reducing energy usage.

Bamboo

Bamboo grows rapidly without pesticides or extensive irrigation. The plant regenerates from its roots, which reduces soil disruption and erosion. Processing methods range from eco-friendly mechanical separation to chemical treatments.

The resulting fabric feels soft against the skin and wicks moisture from the body. Bamboo contains natural antimicrobial compounds that fight odor-causing bacteria. The fibers stretch out when wet and take time to dry.

Bamboo fabric offers minimal UV protection in its natural state. Additional treatments can increase sun protection but reduce the material's eco-friendly status. Bamboo also breaks down faster than synthetics, particularly in chlorinated pools.

The material costs more than standard synthetics due to processing requirements. Its smooth texture resists sand accumulation at the beach. Saltwater degrades bamboo fibers over time, shortening swimsuit lifespan compared to technical fabrics.

Bamboo fabrics are still developing, but many manufacturers already incorporate them into their swimwear lines.

Recycled materials

Recycled fabrics represent a middle ground between eco-friendly and synthetic performance. Recycled plastic bottles and discarded fishing nets can be turned into new swimwear. These reclaimed materials undergo processing to create fibers identical to virgin synthetics. Post-consumer plastic yields polyester, while recovered nylon comes from industrial waste and ocean debris.

The performance matches traditional synthetic swimwear—the molecular structure stays intact through recycling. These fabrics stretch, dry fast, and block UV rays at the same level as standard materials. Swimming pools, salt water, and the sun affect them identically to virgin fibers.

Manufacturing recycled fibers uses less energy and water than creating new synthetics. The process removes plastic from landfills and oceans. Current technology produces high-quality materials from clear and light-colored plastics, though dark bottles pose processing challenges.

Expect some color fluctuation with recycled fabrics due to varying source materials.

UPF-rated fabrics

UPF-rated fabrics block harmful UV rays from reaching your skin through a combination of tight weaves and special treatments. Manufacturers add UV-absorbing particles to the yarn or apply protective coatings. UPF qualities last through chlorine exposure and saltwater immersion. UV treatments bond at the molecular level, so the protection persists through normal wear and washing. 

A UPF 50+ rating means only 1/50th of UV radiation penetrates the fabric. This protection level prevents sunburn and reduces long-term skin damage risks from water-reflected rays. The fabric construction maintains its protective properties even when stretched over curves or wet from swimming.

SwimZip specializes in UPF 50+ fabrics that block over 98% of UV radiation. This rating offers maximum protection for long days in the water. Standard swimwear without UPF treatment permits up to 50% of UV rays to reach your skin.

Otherwise, you can also shop for swimwear in dark colors or with tight weaves. The weave density determines how much light passes through gaps between fibers. Dark colors and tight weaves naturally increase UV blockage beyond the base fabric rating.

Swimsuit textures

Swimsuit textures change how a swimsuit looks and feels on your body. The right texture flatters your shape and adds visual interest to solid-color suits.

• Ribbed: The vertical lines create a slimming effect while adding sophisticated texture. Ribbed textures stretch and conform to your shape to provide extra give in tight areas. Deeper ribs trap sand and show wear along stretch points sooner than flat fabrics. Nylon/spandex blends, polyester/spandex blends, and recycled nylon with elastane can achieve a ribbed texture.

• Smooth: Clean lines showcase prints and create a polished look. These fabrics glide through the water and resist snagging. The flat surface needs minimal care but shows every imperfection in fit and construction. Nylon/spandex blends, polyester/spandex blends, PBT, UPF-rated nylon or polyester, and recycled polyester with elastane can be smooth.

• Textured/patterned: Three-dimensional surfaces add visual interest and camouflage figure concerns. Raised patterns provide grip during water activities but catch on rough surfaces. The texture hides normal wear patterns but can snag or pill over time. These styles typically use nylon/spandex blends, polyester/spandex blends, recycled nylon/polyester with elastane, or UPF-rated textured synthetics.

• Ruched: Gathered fabric flatters curves and smooths problem areas. The layered material provides extra coverage and adjusts to body movement. Ruching requires gentle care to maintain its shape and prevent permanent creases. Nylon/spandex blends, polyester/spandex blends, cotton blends, and bamboo blends can be ruched.

• Velvet: The plush surface creates rich depth and a glamorous sheen. Velvet adds warmth and luxury to any style but flattens when wet. The delicate pile demands special washing and shows wear patterns if not maintained properly. Polyester/spandex velvet, recycled polyester velvet, and cotton-blend velvet can achieve a velvet appearance.

Fabric performance features

Beyond basic stretch and coverage, fabrics determine how your swimsuit handles sun, chemicals, and regular use.

Protection

Shop our sun-protective swimwear collection.

Comfort and fit

Material properties

Polyester dries fastest and stays light in water, while nylon absorbs more moisture but feels softer against the skin. PBT provides a middle ground, balancing quick-drying properties with a smooth feel. Natural fibers offer superior breathability when dry but absorb water and become heavy.

Blend ratios

Higher nylon percentages increase softness but slow drying time, while more polyester speeds drying but stiffens the fabric. Spandex content between 15–25% creates optimal stretch and recovery, though higher spandex percentages increase flexibility at the cost of durability and UV protection.

Fabric weight and construction

Fabric weight affects performance: lighter materials float and move with the body, while dense, tight weaves provide better coverage but restrict airflow. Textured fabrics add grip for better support, whereas smooth fabrics are aerodynamic in the water and adjust easily beneath wetsuits.

Application-specific requirements

Medium-weight fabrics with 20% spandex are best for recreational swimming or other water activities. Competition suits require lighter, more compressive blends.

If you’re only tanning or lounging outside the water, you can opt for heavier fabrics, natural fabrics, and looser fits.

Durability

Sustainability

Sustainability doesn’t currently mix well with swimwear. Natural fabrics are great for coverups and beach accessories, but unless they are blended with synthetics, they lack performance. If sustainability is your goal, opt for recycled materials. They require less energy to refine and help remove plastic waste from our oceans.

Another way to incorporate sustainability is to shop from brands that use high-quality fabrics and construction. Buying fewer swimsuits that look great for longer periods can reduce your overall carbon footprint.

SwimZip offers high-quality, durable swimwear with UPF 50+ fabrics that retain their protective properties and shape through countless beach days—a sustainable choice for eco-conscious shoppers.

How to choose the right swimwear fabric

The right swimsuit material depends on your specific water activities and environment.

Recreational swimming and beach use

 

 

 

Beach and pool lounging require fabrics that stand up to sunscreen, salt, and sand. Nylon-spandex blends are best for casual swimming; the nylon resists abrasion from rough surfaces while the spandex provides comfortable stretch. A blend with 20% spandex moves with your body without losing shape after hours in the water.

Polyester-based suits are also great for frequent beach visits. The fabric repels sand and resists damage from saltwater.

SwimZip's UPF 50+ swimwear blocks 98% of harmful UV rays so you get optimal sun protection during beach activities.

Athletic and competitive swimming

Serious swimmers require technical fabrics that support performance. PBT is the best for competition suits because it reduces water drag while maintaining muscle compression. The material resists chlorine breakdown and maintains its supportive structure.

Some racing suits also blend polyester spandex. A 15–20% spandex content compresses muscles without restricting motion. Look for multiple fabric panels for targeted compression without movement restriction.

Family activities

Family beach days come with unique swimwear challenges. Children's sensitive skin needs soft, non-irritating fabrics. Parents want exceptional UV protection for the whole family and an easy way to spot the children at crowded beaches or pools.

High-grade nylon-spandex blends feel soft against delicate skin while providing unrestricted movement. Look for UPF-rated fabrics that block 98% of harmful rays. Synthetic fabrics also take bright colors and bold patterns better than natural fabrics, which keeps kids visible at a distance. 

SwimZip's family collections pair protective features with coordinated styles. Our matching sets use identical UPF 50+ fabrics across all sizes, so every family member is safe and visible during water adventures.

Water safety needs

 

 

 

Water visibility keeps you or your children safe in the water. Dark swimsuits fade into murky pool or ocean water, while bright colors and neon shades shine through.

Specialized fluorescent dyes, when properly bonded to synthetic fabrics, create swimwear that stands out above and below the water. While light-colored fabrics typically offer less sun protection, advanced UV treatments can provide full protection even in bright neon shades.

SwimZip's neon collection features these high-visibility fabrics with UPF 50+ protection, helping parents spot their children quickly in any water condition.

Special considerations

Sensitive skin demands soft, non-irritating fabrics. Pure nylon blends with minimal additives reduce skin reactions. Seamless construction techniques eliminate chafing points while flat-lock stitches prevent friction marks.

Climate affects fabric performance. Hot-weather swimmers need breathable materials that release body heat. Light-colored fabrics with high UV protection ratings work best. Cold water activities require insulating materials that trap warmth without absorbing water weight.

Frequent swimmers should select fabrics based on exposure type. Daily pool use demands chlorine-resistant PBT or treated polyester. Ocean swimmers need tightly woven fabrics that block sand and resist salt corrosion.

How to care for and maintain swimwear fabric properly

The longevity of your swimsuit depends on proper fabric care. Each material requires specific maintenance to maintain its protective properties and appearance.

Fabric-specific care instructions

Each fabric type has specific care requirements for optimal maintenance:

• Nylon requires gentle hand washing in cool water with mild detergent and no fabric softeners.

• Polyester tolerates machine washing in cold water on gentle cycles with mild soap.

• PBT needs immediate rinsing after pool use with mild detergent.

• Hemp and bamboo require hand washing with natural fiber soap and careful handling.

• High-spandex blends require cool water hand washing without wringing or twisting.

• UV-protective fabrics need mild detergents to preserve their protective coatings.

• Chlorine-resistant materials benefit from immediate fresh water rinses after pool use.

• Color-fast fabrics last longer with color-protecting detergents and cold water.

• Patterned materials should be washed inside out to protect prints and designs.

General washing guidelines

Always pre-rinse suits in cool tap water to remove chemicals and debris. Strong detergents break down fibers and strip protective coatings.

Here are some useful washing practices:

• Turn suits inside out before cleaning.

• Use designated swimwear detergent.

• Only wash in cold water.

• Separate from rough fabrics.

• Skip fabric softeners and bleach.

Drying recommendations

Correct drying prevents fabric damage and maintains suit shape. The heat from dryers destroys elasticity and protective coatings. Direct sunlight fades colors and weakens fibers.

Here are the best practices for drying your swimsuits:

• Roll in clean towels to remove water.

• Lay flat in the shade to dry.

• Avoid hanging by straps.

• Keep away from direct sun.

• Skip the dryer entirely.

How to extend swimsuit life

Regular maintenance prevents premature wear and protects your investment in quality swimwear. Rotating between multiple suits reduces the stress of frequent swimming on any single garment. This practice allows each suit time to dry completely and regain its shape between uses.

Proper pre-swim habits make a significant difference in suit longevity. A quick shower before entering the pool reduces fabric absorption of chemicals. Apply sunscreen at least 15 minutes before you put on your suit to prevent oils from degrading the material.

Post-swim care matters just as much as preparation. Immediate rinsing removes harmful substances before they damage fibers. Freshwater washing dilutes pool chemicals, ocean salt, and sand that wear down the fabric over time. Prompt removal of wet suits prevents bacterial growth and fabric weakening.

Storage conditions affect fabric life as well. Flat storage in cool, dry places prevents permanent creases and elastic strain. Avoid contact with rough surfaces to protect against snags and tears. Separate light and dark suits to prevent color transfer.

Signs of fabric deterioration

Early detection of wear prevents suit failure. Watch for these indicators of fabric breakdown:

• White patches signal chlorine damage.

• Loose threads indicate seam failure.

• Baggy areas show elastic breakdown.

• Pilling appears in friction zones.

• Fading suggests coating failure.

Once your swimsuit shows signs of deterioration, you’re ready to buy a new one. And armed with your new fabric knowledge, you’re also ready to make a better choice.

Shop our swimwear today.

Swimwear fabrics FAQ

What makes swimwear quickly dry?

Synthetic fibers such as polyester and PBT repel water molecules and cause moisture to evaporate rapidly. Lightweight heft and tight weave construction also speed up drying by preventing water absorption into the fabric core. Modern moisture-wicking treatments boost this natural quick-dry property.

What material is common for making swimsuits?

Nylon and polyester dominate the swimwear industry. Polyester swimwear leads the market because of its durability and chlorine resistance. Manufacturers blend these materials with spandex to create suits that maintain shape while providing the necessary stretch for water activities.

What type of fabric is the most chlorine-resistant?

PBT offers superior chlorine resistance because its molecular structure actively repels chlorine particles. High-quality fabric treatments can improve other materials' chlorine resistance, but PBT naturally maintains its strength and color after hundreds of hours in treated pools.

What kind of fabric is a 4-way stretch?

Four-way stretch fabric stretches lengthwise and crosswise to provide maximum flexibility in all directions. It combines synthetic base fibers with spandex to create dynamic stretch and recovery. This construction proves essential for athletic swimwear that demands unrestricted movement.

What swimsuit fabric works best for different body shapes? 

Different fabrics flatter different body shapes. For example, polyester blends offer structure and support for curves, and elastane fabric adds control for athletic builds. Rib-knit fabrics contour naturally to all figures.

Which fabrics resist sun damage best? 

Fabrics with high sunlight resistance maintain their integrity longer. Mildew-resistant synthetics withstand sun and water exposure. Dark colors and treated materials show less color fading than untreated light shades.

What sustainable swimwear options exist? 

Sustainable choices include recycled polyester and biodegradable nylon. These eco-friendly materials offer the same performance as virgin synthetics. Natural fibers (e.g. hemp) provide another sustainable fabric alternative.

How do materials differ for competitive versus recreational swimming? 

Competitive swimmers need technically advanced synthetics that reduce drag. Swimming costumes for recreational use prioritize comfort and durability. The fabric surface affects water flow differently for each activity type.

What causes swimsuit fabrics to wear out quickly? 

Fabric that traps moisture breeds bacteria and breaks down faster. Poor-quality polyester blend fabrics may pill or stretch. Improper care of ribbed swimsuit materials can also cause permanent creasing.

Why do some swimwear fabrics cost more than others? 

Premium materials offer superior performance and longevity. While basic options are a popular choice, higher-end materials are an excellent choice for those who need enhanced performance or who want the best styles and swimsuit longevity.

Further reading

Complete guide to bikinis

What are polarized sunglasses?

What color is least visible underwater?

What is UPF clothing?

What does tanning oil do?