Swimwear is almost always made from 100% synthetic fabrics. Polyester, nylon, elastane, are just the norm.
But long before plastics became standard, people swam in wool. And interestingly, modern fine Merino wool still performs beautifully in water.
I didn’t originally set out to design swimwear. It happened organically, the way many of our Simply Merino pieces do.
It Started With Underwear
We had already made our Merino wool underwear and bralette. They were designed to be breathable, soft, and comfortable enough to live in.
Then something interesting started happening.
Customers began asking, “Can you swim in these?”
Some told us, “We already are.”
I wasn’t surprised, because I was doing the same thing.
I already loved swimming in Simply Merino underwear. If I was heading to the ocean or a lake, I would already be wearing it and I would just swim in it. It felt natural, comfortable, and supportive without feeling restrictive.
That’s when it clicked.
If our customers were swimming in their underwear… and I was swimming in mine… why not intentionally design a swimsuit built from that same idea?
So I did.
I created the Simply Merino swimsuit three years ago, in 2023, because it was what our community was asking for.
Wool Insulates — Even When Wet
One of wool’s most remarkable properties is its ability to retain warmth, even after absorbing moisture.
Unlike cotton, which loses its insulating ability when saturated, wool fibers maintain their structure. The natural crimp in the fiber traps air, helping preserve thermal insulation in damp conditions¹.
For lake swims, ocean dips, or shoulder-season beach days, that insulation can make a noticeable difference, especially once you’re out of the water.
It Regulates Temperature in and out of the Water
Merino wool doesn’t just insulate, it regulates.
Wool fibers can absorb moisture vapour (up to about 30% of their weight) without feeling wet². That means when you transition from water to air, the fabric doesn’t feel clammy against your skin the way many synthetics can.
I’ve always loved how it softens the post-swim chill. You don’t feel that sharp temperature drop as intensely.
Naturally Odour Resistant
Swimwear goes through a lot: salt water, sunscreen, sweat, long beach days. Synthetic suits can hold onto odour over time.
Wool fibers, however, can bind and trap odour molecules within their protein structure³. That means less odour buildup and less frequent washing.
For travel especially, this is one of my favourite benefits.
A Different Kind of Stretch and Feel
Wool swimwear feels different than conventional swimsuits. They are softer, less compressive, and more natural.
Fine Merino has inherent elasticity because of its fiber crimp, allowing it to stretch and recover without relying entirely on synthetic fibers. It moves with your body instead of feeling tight or restrictive.
It’s not designed for competitive pool racing or heavy chlorine exposure. But for:
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Lake swims
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Ocean dips
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Paddle boarding
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Sauna-to-cold-plunge cycles
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Slow beach days
It performs beautifully.
A More Thoughtful Alternative
Traditional swimwear is petroleum-based and sheds microplastics during washing and wear. Synthetic textiles are estimated to contribute significantly to primary microplastics entering oceans annually⁴.
Merino wool is natural and biodegradable. Even if tiny fibers shed, they break down far more readily in the environment than synthetic microplastics⁵.
That matters to me. And it matters to many of you.
Why I Still Swim in My Underwear
The funny thing? I still swim in my Merino wool underwear and bralette sometimes — because I’m already wearing it.
That’s really the heart of this design. Versatility. Simplicity. Pieces that work harder so you can pack less, own less, and live more freely.
The swimsuit wasn’t created in a design meeting.
It was created from real life. Mine and yours. That’s still how we design today.
🖤 Shannon
References
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Holcombe, B. V. (1983). Moisture sorption and transport in wool. Textile Research Journal.
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Laitala, K., Klepp, I. G., & Henry, B. (2018). Does use matter? Comparison of environmental impacts of clothing based on fiber type. Sustainability, 10(7), 2524.
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Bai, W., et al. (2023). The adsorption kinetics and mechanism of odorous gases onto textile fibers. RSC Sustainability.
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International Union for Conservation of Nature (IUCN). Primary Microplastics in the Oceans: A Global Evaluation of Sources.
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Napper, I. E., & Thompson, R. C. (2016). Characterisation, quantity and sorptive properties of microplastics from washing synthetic textiles. Environmental Science & Technology.
