Why we chose 100% cotton over polyester.

Most polo shirts you can buy on the high street right now are made of plastic.

That sentence sounds dramatic, but the chemistry isn’t ambiguous. Polyester is a synthetic plastic fibre — polyethylene terephthalate, the same family as the plastic in single-use water bottles. Around 60% of all clothing produced globally is now polyester or polyester-blend, up from less than 25% in the year 2000.¹

We thought about it for a long time. Then we made our choice — every apparel piece in Adler Sterling Drop 01 is 100% cotton or cotton-linen, never blended with synthetics. Here’s what shifted our thinking, and why we think it should shift yours.

The microplastic problem isn’t theoretical

Synthetic clothing sheds microplastic fibres every time it moves, washes, and dries. The numbers are sobering.

A landmark 2016 study at the University of Plymouth measured the microfibre release from a single 6kg load of synthetic clothing in a domestic washing machine. The result: between 137,000 and 728,000 microfibres released per wash, depending on the fabric mix.² Acrylic was worst, followed by polyester-cotton blends, then pure polyester.

Those microfibres don’t disappear. They flow through wastewater treatment plants — which were never designed to filter microscopic plastic — and end up in rivers, oceans, and the food chain. The Royal Society for Public Health has flagged textile microfibres as one of the most significant uncontrolled sources of marine microplastic pollution.³

The really uncomfortable bit: microplastics have now been measured in human blood. A 2022 study in the journal Environment International tested 22 anonymous adult blood samples and found microplastic particles in 17 of them — including PET (polyester), polystyrene, and polyethylene.⁴ We don’t yet fully understand the long-term health implications. We do know we’d rather not be part of the supply chain that creates the problem.

And then there’s the day-to-day stuff

Beyond the bigger environmental picture, polyester has practical problems that anyone who’s worn it for a hot day knows.

It doesn’t breathe. Cotton is a hollow natural fibre — it absorbs moisture and lets air through, which is why a 100% cotton tee feels cool when it’s hot out. Polyester is a sealed plastic strand. It traps sweat against your skin and stops your body from regulating temperature properly. The British Association of Dermatologists has noted that synthetic fabrics can exacerbate skin irritation and prickly heat in warm conditions.⁵

It holds odour. Bacteria thrive on polyester’s surface in a way they don’t on cotton — the chemical structure of polyester traps the volatile organic compounds that bacteria release as waste, creating that distinctive synthetic-shirt smell after one wear.⁶

It pills. Polyester doesn’t biodegrade in your wardrobe — it photodegrades. It looks fine for the first few months, then starts pilling, fading, and feeling cheap. Cotton ages quietly; polyester ages loudly.

Cotton isn’t perfect either

We’re not pretending cotton is a clean choice. Conventional cotton is one of the most water-intensive crops in agriculture and historically one of the most pesticide-heavy. The Better Cotton Initiative estimates that conventional cotton accounts for 16% of global insecticide use despite covering just 2.5% of arable land.⁷

Where we can, we work with suppliers using BCI-compliant cotton or organic cotton certified to GOTS (Global Organic Textile Standard). Where we can’t yet — the smaller capsule pieces, the foundation socks, the cotton-linen blends — we’re transparent about it and we’re working on it.

But “imperfect natural fibre” beats “perfect synthetic” every time when the synthetic is shedding plastic into your bloodstream and the ocean.

What this means for Drop 01

Every apparel piece in our Drop 01 catalogue is 100% cotton or cotton-linen:

Heavyweight Tee — 280gsm pure combed cotton
Heritage Polo — 100% cotton with a silk-finish weave
Henley Linen Shirt — cotton-linen blend
Foundation Trousers — pure cotton
Mediterranean Wide Leg — cotton-linen
Foundation Boxer Brief 6-Pack — combed cotton
Combed Cotton Dress Socks 5-Pack — 95% combed cotton (small elastane content for fit retention)

No polyester. No acrylic. No nylon blends. No “performance fabric” that’s just polyester with a marketing department.

The trade-off we’re asking you to accept

Cotton costs more. It takes longer to dry. It wrinkles. It needs a slightly more attentive laundry approach (cool wash, hang dry, iron on low if you must).

We’re asking you to accept those trade-offs because the alternative is wearing plastic against your skin, every day, for the rest of your life — and shedding it into the water system every time you wash a load.

We think it’s a fair ask.

Drop 01 launches 21 May 2026. The waitlist is on the homepage and subscribers get 15% off their first order with code CLAIM15.

— Mounir

Sources

Textile Exchange. Preferred Fiber & Materials Market Report 2023. https://textileexchange.org/knowledge-center/reports/preferred-fiber-and-materials/ ↩
Napper, I. E., & Thompson, R. C. (2016). “Release of synthetic microplastic plastic fibres from domestic washing machines: Effects of fabric type and washing conditions.” Marine Pollution Bulletin, 112(1-2), 39-45. https://doi.org/10.1016/j.marpolbul.2016.09.025 ↩
Royal Society for Public Health (2019). Microplastics in the marine environment. https://www.rsph.org.uk/ ↩
Leslie, H. A., et al. (2022). “Discovery and quantification of plastic particle pollution in human blood.” Environment International, 163, 107199. https://doi.org/10.1016/j.envint.2022.107199 ↩
British Association of Dermatologists. Skin care and clothing guidance. https://www.bad.org.uk/ ↩
Callewaert, C., et al. (2014). “Microbial odor profile of polyester and cotton clothes after a fitness session.” Applied and Environmental Microbiology, 80(21), 6611-6619. https://doi.org/10.1128/AEM.01422-14 ↩
Better Cotton Initiative. About BCI: Why we need better cotton. https://bettercotton.org/ ↩