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Six shades, one perfected fit
Organic cotton string thong underwear with a barely there feel, created to disappear under clothing.
Six shades designed to complement a range of skin tones.
Build your everyday set across the six shades.

Woman modeling String Nix black seamless thong underwear.
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Organic Cotton String Thong Black
Woman modeling String Nix white seamless thong underwear
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Organic Cotton String Thong White
Woman modeling String Nix nude seamless thong underwear
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Organic Cotton String Thong Almond
Woman modeling String Nix brown seamless thong underwear
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Organic Cotton String Thong Caramel
Woman modeling String Nix dark brown seamless thong underwear
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Organic Cotton String Thong Cinnamon
Woman modeling String Nix chocolate brown seamless thong underwear
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Organic Cotton String Thong Chocolate

Let customers speak for us

from 16 reviews
Superb quality

Superb quality, and great colours! Long lasting & wash amazingly! Definitely worth the purchase - my first ones are still going years & years later

Liz
03/17/2026
Organic Cotton String Thong Chocolate
Organic Cotton String Thong Chocolate
Love them! Tried and tested

I bought six pairs about a year ago and they have been so good. Really comfortable, soft, and they sit well under clothes without showing. A year on, they are still the pairs I reach for first. I have washed them loads and they have held up far better than I expected. Expensive, yes, but worth it. showing. A year on, they are still the pairs I reach for first. I have washed them loads and they have held up far better than I expected. Expensive, yes, but worth it. e pairs I reach for first. I have washed them loads and they have held up far better than I expected. Expensive, yes, but worth it.

Caroline Aby
03/15/2026
Organic Cotton String Thong White
Organic Cotton String Thong White
Amazing fit, I would definitely recommend!! ❤️

These knickers are made from certified organic cotton and you can really feel the difference, super soft, breathable, and kind to my skin. The fit is amazing even after washing, I’d definitely recommend!! ❤️

Natalie C
10/15/2025
Organic Cotton String Thong White
Organic Cotton String Thong White
A new level of comfort

I’ve got two pairs in different colours - these are the best knickers I’ve got by a long shot. They’re so comfortable, the size fits perfectly and you can feel the fabric quality. I will definitely get more!

Filipa
09/26/2025
Organic Cotton String Thong Black
Organic Cotton String Thong Black
Best String Thong Undies On the Market!

The Almond thong in an 8 is a great fit and true to size, really comfortable and lovely soft material . I’ve been looking for something like this for ages and I’m so glad I found it.

Sally B.
09/26/2025
Organic Cotton String Thong Almond
Organic Cotton String Thong Almond
Amazing pants!

I’ve tried countless undies brands over the years, including some of the big names, and nothing comes close in terms of comfort, fit, and quality.

The organic cotton is lovely and soft without being flimsy, and the recycled elastic, (didn’t even know that was a thing) gives the right amount of support without cutting in.

I like that String Nix is built around everyday luxury essentials. It doesn’t feel like it’s trying too hard, it just is better.

No fast-fashion rubbish just beautifully made Nix and I’ve already recommended them to friends. I’ll be buying more, they are a game-changer.

Lozzzzzurrr
06/24/2025
Organic Cotton String Thong Chocolate
Organic Cotton String Thong Chocolate
So happy to wear them❤️Absolutely love them❤️

I really like this product, they are extremely comfortable and don’t have any VPL at all. Can’t recommend enough, thank you.

Yuna
01/25/2025
Organic Cotton String Thong Black
Organic Cotton String Thong Black
Comfortable and Eco friendly

I was hesitant to try a new brand of string thong after years of searching for the perfect one, but Stringnix changed my mind. Made from organic cotton and recycled materials, it’s both eco-friendly and incredibly comfortable. It’s also ideal for Pilates and running, offering a seamless, no-VPL fit. I’d recommend sizing down, as the fit is quite generous, especially at the front.

Caroline Dingwall
01/25/2025
Organic Cotton String Thong Black
Organic Cotton String Thong Black
Excellent

I love my Nix, the quality is amazing and so comfortable.

L.A.
10/07/2024
Organic Cotton String Thong Black
Organic Cotton String Thong Black

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