Why Are Swimsuits Made of Synthetic Fibres?

Why Are Swimsuits Made of Synthetic Fibres?

The best swimsuit fabric is a topic of hot debate in the fashion world. But the truth is that there really aren’t a ton of options.

Swimwear fabrics typically must be quick-drying, colourfast, and have a certain amount of stretch.

Let’s discuss some of the different options for swim fabrics and their various characteristics. 

The earlier swimwear range used to come in cotton or woollen fabric, but they were not quite good enough as stretchier, used to absorb water much and didn’t hold up to chlorine.

So the designers and manufacturers then looked at other befitting options and came up with – synthetic materials.

The best fabric for swimwear is a polyester/elastane blend. Elastane is the super stretchy fabric better known by the brand names Spandex or Lycra.

Polyester is colourfast and resistant to chlorine, making it a perfect choice. Nylon is another good fabric for swimwear, but it is more likely to be pill over time.

Swimwear fabric has to be comfortable and durable. When combined with elastane, polyester and nylon have similar qualities. So let’s take a look at how each one performs in swimwear.

All You Need to Know About Swimsuit Fabric

Most swimsuit fabric is meant to stretch to fit all those gorgeous curves and to allow for a comfortable and safe swim.

However, the fabric also needs to be able to both hold its shape when wet and dry easily and quickly. For this reason, almost every type of swimwear fabric contains elastane fibres.

Elastane is a synthetic fibre with elastic qualities that revolutionized the fashion industry when it was developed in the 1960s. Elastane is the generic name for Lycra or Spandex.

But, of course, Lycra, Spandex, and elastane are all the same thing, so don’t get hung up on the branding.

Elastane is blended with other synthetic fibres to provide a comfortable stretch.

The blend varies based on the manufacturer and the desired qualities of the fabric, but generally, it is made with around 10%-20% elastane to 80%-90% other fibre (s).

Is Swimwear Fabric Important?

Selecting the best swimsuit material for training or competition can be tricky. With all the quality brands on the market today, the choices can be somewhat overwhelming: Kiefer, Speedo, TYR, Arena, and Dolfin.

In addition, the choices vary between what style, colour or pattern, and fabric.

The selection of swimsuit fabric is very important and should reflect your goals as a swimmer: are you looking for the best fit, durability, stretch – or all of the above? Your choice of swimwear is vital to meeting your expectations.

What Material Are Swimsuits Made Of?

Natural Fabrics

Before the invention of synthetic fibres or stretchy Lycra, swimsuits were made from natural fibres.

Weirdly enough, wool was one of the most popular. The thinking behind the use of wool is that it has a certain amount of elasticity to be knitted into close-fitting swimwear.

Wool was also readily available and affordable, meaning swimmers could knit their swimming costumes.

There were knitting patterns in fashion magazines to enable them to do this. It was slightly bizarre from a modern-day perspective, but it was all they had back in the days before Spandex and Lycra.

One of the leading names in swimwear today, Speedo, started as a knitting factory making socks.

Like most natural fibres, wool tends to soak up water. This causes it to expand, become heavy and stretch out of shape. None of which are endearing qualities when it comes to bathing suits.

With the recent push for more sustainable options, wool and polycotton blends slowly make their way back into swimwear.

However, there’s still a long way to go before natural fabrics can come close to the superior swimming experience offered by synthetic materials.

Until then, natural fibres will continue to be ruled out when choosing suitable fabrics for swimwear.


Polyester fabric has dominated the competitive swimwear industry for several years. Whether blended with Lycra® or by itself, polyester is the leading fabric for competitive swimwear.

New technologies in polyester have improved the hand and feel of the material, allowing it to surpass other fabrics. 

Soft fabric with incredible durability, polyester is one of the most popular fabrics in apparel construction.

Its quick-drying properties and longevity make it a great choice for swimwear, especially for competitive swimming.

With built-in UV resistance and the ability to withstand regular contact with chlorine, this fabric is a top choice for any garment likely to be used on the beach or by the pool.

Synthetic Fabrics

The list of synthetic fibres and blends of fibres is endless for suitable fabrics for swimwear.

Synthetic materials are brimming with the essential qualities today’s swimwear needs to perform in both competitive sports and fashion arenas.

Topping the choice of suitable fabrics is polyester. A fabric with built-in resistance to chlorine and sunlight, it’s both easy to care for and durable.

When blended with the stretch of elastane, the inherent qualities of polyester make it the perfect option for swimwear.

There are different combinations of polyester-elastane blends. Some fabrics will contain more polyester, others more elastane.

The result is the same, though. A fully functional, resilient piece of clothing designed to be a hit in the pool or by the beach.

Elastane can be blended with other fabrics besides polyester. Going by the names Spandex or Lycra, elastane can be coupled with nylon to create a swimwear fabric.

Unfortunately, nylon is less UV resistant and can be damaged by chlorine.

However, it’s still a suitable alternative to a polyester-based garment, especially if you are looking for a one-season fashion swimsuit.

Less popular but just as comfortable is a polycotton-spandex knit fabric. This option combines the look and feel of polycotton with the stretch needed for swimwear.

It comes with some disadvantages. Being part-natural fibre affects its ability to dry quickly, and it tends to fade at a faster rate.

Despite this and depending on the ratio of polyester to cotton, this fabric has the potential to be a durable and viable choice.


Also known as Polyamide, nylon is quick-drying and water-resistant. Found primarily in fashion swimwear, it is incredibly comfortable and flattering to wear.

Nylon is most typically recycled using “pre-consumer” material, which is somewhat less eco-friendly than post-consumer. This means that the materials come from a stream of waste that the consumer has not yet used.

Being upstream of the consumer means that this material has not yet been used by the consumer, which means it’s closer to “raw” than post-consumer material.

In addition, the source of this material can sometimes be a bit suspicious, making it easier to “green-wash” this recycled product.

However, Econyl, a recycled nylon swimwear fabric, has gotten enormous press for its use of fishing industry waste in its recycled nylon filament.

Other companies have begun producing recycled polyester fabric products as well.

While there is some debate about the environmental impact of the recycling process itself, there can be no doubt that upcycling plastic waste into the fashion industry is a good thing. 

Nylon fabric is an alternative fabric to polyester. Nylon is lightweight and offers a smooth fit.

However, nylon fabric has its disadvantages as it is not chlorine resistant and not as long-lasting as polyester. 

Soft with a slightly glossy sheen, the fabric looks and feels attractive.

When mixed with elastane, the fabric can be figure-hugging, which can help hide body fullness.

Because of this, it has become a popular material for swimming costumes, pools, and beachwear.


Elastane was developed for apparel use in the late 1950s. It’s the generic name for the elastic fabric found in brands like Lycra and Spandex.

A 100% synthetic material, elastane is polyurethane.

Originally introduced to replace rubber, it also has a wide range of industrial applications, including shock and heat insulation.

Elastane can be used with synthetic materials or added to natural fibres to give garments a comfortable stretch. In addition, its elastic properties make it an ideal fabric for swimwear.


PBT for short, Polybutylene Terephthalate or PBT is a plastic yarn fibre with natural stretch and recovery. PBT is a member of the polyester family of plastics.

Not as stretchy as other polyesters, its texture is stiffer with a light and smooth feel.

Coupled with the slightly duller or matte finish, the material glides through the water. Again, an attribute is making it fantastic for competitive sportswear.


Historically natural fibres like wool or cotton would have been used to make bathing costumes. Think Victorian beach-goers with their full body-covering outfits.

One of the main problems with natural fibres is water retention. Clothing can absorb too much water causing the swimmer to sink.

Or worse, lose their swimsuit as it pulls out of shape and falls off.

These days, cotton and bamboo are used to create retro swimwear reminiscent of by-gone days.

These outfits are not designed for regular or competitive swimming; they’re more for beach-lounging or relaxing on a deck chair.


Neoprene is a synthetic rubber and not technically a fabric. Used for wetsuits, neoprene is the inner layer of insulating foam, keeping divers and surfers warm.

Particularly in winter or in seas known to be chilly all year round.

The reason they are called wetsuits is that water is trapped close to the skin. As body heat warms the water, the diver’s body temperature is kept at a comfortable level.

One disadvantage with neoprene, the divers’ bodies are always wet.

Scuba Fabric

Sometimes confused with neoprene, scuba fabric is double-knit with lots of stretches.

Like a Ponte knit in construction, the fabric is quite stiff and used to create structure in garments. Although it lacks the inner layer of insulating foam, scuba’s overall look and feel are similar to neoprene.

Not being as flexible as a polyester-spandex mix, your scuba suit might restrict movement in activities like volleyball.

But, if a structured wetsuit look is one you are looking for in your swimwear, scuba is the choice for you. Durable, resilient, and fully opaque, it’s a great choice for both style and modesty.

Frequently Asked Questions About Swimwear

Which fibre is used for making swimsuits?

Swimsuits are made up of Nylon or blending with other fibres like lycra or spandex. nylon observes little water and dries very quickly.

Nearly all swimwear fabric has a percentage of spandex in the fabric because of its elasticity.

Are swimsuits synthetic?

When it comes to swimwear, the best fibre content for your fabric is stretchy synthetic.

Created by blending either polyester or nylon with elastane, swimwear fabrics are naturally durable, water-resistant, and quick-drying.

Can you wear spandex in the pool?

Spandex is a stretchy material that offers a very good, comfortable fit. Spandex is known for its elasticity and stretch, which is ideal for swimming.

Spandex suits must be rinsed in cool water after each use, and don't hold up as well with the harsh chemicals of the pool which can lead to discolouration of the suit.

What to Consider When Looking For Swimwear Fabric?

The last thing you need in a swimwear fabric is for your bikini or swimming shorts to turn see-through underwater.

A fabric that shrinks when wet can also cause a few embarrassing problems.

Look and Feel

Swimwear fabric needs to look good and help you feel confident. It should be soft, flexible, and have an attractive design or print.

Let’s face it, and most modern-day swimsuits leave little to the imagination. What’s on show needs to look fantastic, so you don’t feel anxious wearing the garment.

The fabric should enhance your assets, not detract from them. Avoid neon colours if you are at all body-conscious.


An uncomfortable swimming costume is going to hamper your enjoyment severely.

As well as your freedom of movement. A swimwear fabric needs to be flexible enough to allow your body to move.

It also needs to be soft enough to prevent rubbing and chaffing.

When it comes to swimwear, the softer the material, the better.


Swimsuits are designed to be close-fitting.

The closer the fit, the less likely they’ll accidentally fall off underwater. To be figure-hugging, the fabric has to be flexible and stretchy.

Unfortunately, many swimwear is made with negative ease, meaning there isn’t much space available when you’re wearing it.

Make sure your fabric has the necessary stretch to accommodate both you and your need to breathe. Try to find fabric with a four-way stretch with at least a 60-70% stretch in any direction.


Swimwear fabric needs to be durable and resilient. It comes into contact with pool chemicals and UV rays, and both can cause degradation.

A key element for any fabric used in swimsuits is the ability to resist damage caused by chlorine, sunshine, and other abrasive substances like sea salt.


This is a hard box to tick when it comes to swimwear.

The best fabrics are synthetics due to the resilience, durability, and flexibility inherent in the material. Unfortunately, synthetics are also the least sustainable of all fibres.

Many are petroleum-based and rely heavily on fossil fuels. All is not lost, though. By considering recycled materials, you can go a long way to counteracting the environmental impact of your swimsuit.


Fabric for swimwear can vary in price.

The choice is down to your budget, from the inexpensive polyester-based materials to the slightly higher cost of a nylon garment.

The ideal fabric for your swimwear should be the best quality you can afford.

Ensure the material has longevity, and the investment you make in your swimsuit will repay you with a garment that will still look good after multiple swims.

The best fabric for swimwear is a stretchy synthetic with chlorine and UV resistance. Knowing what to look for will help you choose your fabric with greater confidence.

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