There’s one thing that unites modern swimwear: synthetic fabric.

No matter the style or price tag, glance at the label inside any contemporary swimsuit and you’re sure to find it has been crafted from high-stretch polyester, nylon or elastane. In today’s rapidly growing swimwear market, synthetics reign supreme. 

This hasn’t always been the case. When swimming for leisure first came into fashion at the turn of the 20th century, modest bathing suits were made from natural fabrics such as cotton or wool. In fact, many legacy swimwear brands started off as knitting factories, constructing swimming costumes from ribbed woollen knits. Although these early designs were form-fitting and had a small amount of stretch, the fabric’s absorbent nature meant they took on water, becoming heavy and misshapen when wet.

It wasn’t until the mid 1920’s that synthetics came into the frame. In 1925, the American Rubber Company invented an elastic latex rubber called Lastex, which became a popular fabric choice for swimsuit manufacturers around the globe. Thirty years later, the invention of nylon and lycra saw swimwear move away from natural fabrics for good.

The appeal of synthetics is clear. Lightweight, flexible, hard wearing, water-resistant, quick-drying, elastic and chlorine and UV-resistant, they can be made into long-lasting swimsuits that comfortably fit to the body and allow effortless movement. Synthetic fibres are also cheaper than their natural counterparts, so are widely used by fast-fashion brands to produce inexpensive pieces. It’s no wonder that an estimated 65 percent of all fibres produced each year are synthetic. 


"an estimated 65 percent of all fibres produced each year are synthetic


However there are considerable downsides to the swimwear industry’s use of synthetics. When washed, polyester, nylon and other plastic-based fabrics shed microfibres that enter our oceans, harming sea life and marine ecosystems. A report by the World Economic Foundation predicts that the weight of plastics will overtake the weight of fish by 2050. This can be dramatically reduced by using Guppyfriend Washing Bags or Cora Ball when washing synthetics in the washing machine, to catch microfibres and prevent them being released into the water stream.

Synthetic fabrics have other negative environmental impacts. The production of virgin fibres uses valuable non-renewable resources, such as oil and natural gasses. Plus, toxic chemicals are often used in the manufacturing process. Unlike natural fabrics, most synthetics don’t biodegrade, remaining in landfill for up to 200 years.

If we are to protect our planet, the synthetics status quo needs to radically change. Fortunately a new wave of regenerated materials such as Econyl® is doing just that. 

Made from post consumer waste, ECONYL® helps reduce the use of virgin nylon fibers. What's more, fabrics made with ECONYL® have all the comfort and performance benefits of traditional synthetic fabrics and come with the added benefit of not using new oil resources to be made. This is why at Kōraru, we use these fabrics to craft each and everyone one of our love-forever sustainable swimsuits. 

Kumanomi luxury swimsuit from Koraru in off-white Avorio shade