Most swimwear sold today lists a fabric composition on the label. Something like 80% nylon, 20% elastane, or 78% polyester, 22% Lycra. These numbers matter, but they do not tell the whole story. The ratio of nylon to elastane affects how the suit stretches, how quickly it recovers, and how long it holds its shape. Here is what we look at when we select fabric for the Rivage and Soleil.

Why nylon and not polyester

Polyester is cheaper and more widely available than nylon. It is also less resistant to chlorine degradation and has a slightly different hand. It tends to feel stiffer and less smooth against the skin. Nylon absorbs a small amount of water, which means it dries slightly more slowly than polyester, but it also drapes better and holds colour more evenly over time. For a piece that will be worn in salt water and sun repeatedly, nylon is the more durable choice. The recycled nylon we use, sourced from a mill in Fukui Prefecture, is made from post-consumer fishing nets and industrial waste.

What the elastane percentage does

Elastane (also sold as Lycra or spandex) is the component that gives swimwear its stretch and recovery. A higher elastane percentage means more stretch but also faster degradation. Elastane breaks down with repeated exposure to chlorine and UV. Most performance swimwear sits between 15% and 25% elastane. Our Rivage fabric is 18% elastane, which gives enough stretch for a secure fit without sacrificing longevity. We tested samples at 22% and found the recovery was slightly worse after 30 wash cycles.

How to read a fabric composition label

The percentages on a label refer to the weight of each fibre in the finished fabric, not the volume. A fabric that is 82% nylon and 18% elastane contains more nylon by weight than elastane, but because elastane fibres are much finer, the elastane threads are woven through the fabric at a higher density than the numbers suggest. This is why a small change in elastane percentage has a noticeable effect on how the fabric feels and behaves.

Caring for recycled nylon swimwear

Rinse in cold fresh water immediately after swimming, especially after contact with chlorine or salt water. Both degrade elastane faster than fresh water. Hand-wash with a gentle detergent and lay flat to dry. Do not leave a wet swimsuit in a bag for hours before rinsing. The combination of heat, salt, and chlorine in a confined space accelerates fabric breakdown significantly. We have seen suits that were rinsed consistently last four or five summers. Suits that were not rinsed regularly showed visible degradation after one.

If you want to see and feel the fabric before ordering, we keep samples of all our current swimwear fabrics at the atelier. Book a fitting appointment and we will set aside time to go through them.