Why We're Done With Polyester (And What We Wear Instead)
Look down at what you're wearing right now.
There's a decent chance it has polyester in it — maybe even a lot of it. In fact, synthetic fibers now make up 64% of the global fiber market, and polyester is the dominant one. It's in our blouses, our dresses, our "linen-look" tops that aren't actually linen at all.
At Sunday Supply, we built our entire brand around one simple belief: you shouldn't have to wear plastic to get dressed.
That's not just a preference. It's a conviction backed by a growing body of research — and once you understand what polyester actually is and what it does to your body and your world, it's hard to go back.
What Is Polyester, Really?
Let's start with the basics, because most of us were never told.
Polyester is a synthetic fiber made from petroleum. It is, quite literally, plastic spun into thread. The technical name — polyethylene terephthalate, or PET — is the same material used to make plastic bottles.
That silky-looking blouse from a fast fashion site? Plastic. That flowy sundress for $19.99? Plastic. The "breathable" athletic top you've been wearing to the gym? Often plastic.
None of this is hidden. It's just never framed that way.
The Problem With Wearing Plastic
1. Polyester Doesn't Breathe — Your Skin Does
Your skin is your body's largest organ, and it needs to breathe. Natural fibers have small gaps between their fibers that allow air to move freely, help your body release heat, and let sweat evaporate. Polyester does none of this well.
Cotton can absorb up to 25 time
s its weight in water without feeling wet. Polyester absorbs less than 1% of its weight — meaning sweat and heat have nowhere to go. The result: discomfort, clamminess, trapped odors, and for many people, skin irritation and breakouts.
Linen absorbs moisture quickly and releases it into the air, keeping skin cool and dry. Silk regulates temperature naturally,
staying cool in heat and warm in cold. Cotton allows constant airflow. Polyester does the opposite of all of these.
2. It Sheds Microplastics — Into You, and Into the World
Here's where it gets harder to ignore. Every time you wash a polyester garment, it sheds microplastic fibers. A single wash cycle can release between 8,800 and 6.8 million microplastic fibers from one garment. Over the course of a year, one person releases nearly 300 million polyester microfibers through laundry alone.
Those fibers end up in waterways, in soil, in seafood — and ultimately in us. Microplastics have now been detected in human blood, lungs, liver, and reproductive tissue. A 2024 study in The New England Journal of Medicine found that patients with microplastics in their arterial plaque had a 4.5 times higher risk of heart attack, stroke, or death compared to those without.
Clothing is the world's largest source of primary microplastics, accounting for approximately 35% of the total in our oceans.
And if you've been reassured by "recycled polyester" — the supposedly eco-friendly choice — recent research from the Changing Markets Foundation found that recycled plastic fabrics release around 55% more microplastics than virgin polyester, and the fibers released are on average 20% smaller, making them easier to absorb through skin and into the bloodstream.
3. It Can Irritate Your Skin
Polyester is not as breathable as natural fibers, which can lead to discomfort, excessive sweating, and trapped odors. For those with sensitive skin, eczema, or allergies, the chemical coatings and dyes used in polyester production can trigger reactions. Tight, non-breathable synthetic fabrics can also disrupt the skin's natural environment — particularly in areas most sensitive to heat and moisture.
Natural fibers like cotton, silk, and linen are hypoallergenic, gentle on sensitive skin, and free from the synthetic treatments that polyester requires to function. Linen in particular is naturally antimicrobial and resistant to bacteria and allergens — properties it has without needing to be engineered.
4. It Doesn't Last, and It Doesn't Age Well
One of polyester's selling points is its durability. But "durability" in synthetic fabrics often means it resists biodegradation for hundreds of years in a landfill — not that it looks good after 50 washes. Polyester pills, fades, retains odors over time, and gradually loses whatever drape and softness it started with.
Natural fibers do the opposite. Linen gets softer with every wash. Silk becomes more supple. A well-made cotton top can look better in year three than it did on day one. These are fabrics that age with you.
What We Wear Instead
At Sunday Supply, we work exclusively with four natural fibers. Here's what each one brings to the way you get dressed.
Linen
Made from the flax plant, linen is one of the most breathable fabrics in existence. It's naturally antibacterial, moisture-wicking, hypoallergenic, and gets softer with every wash. Linen is also one of the most sustainable fibers available — flax requires very little water to grow and no synthetic pesticides. If you've ever put on a well-made linen top on a warm day and felt immediately, inexplicably at ease, that's not an accident. It's the fabric doing exactly what it was designed to do.
Silk
Silk is a protein fiber, meaning it's structurally similar to human skin. It creates almost no friction against the body, which reduces irritation and helps skin retain its natural moisture. Silk regulates temperature beautifully — cool against warm skin, warming in cooler air. It has a natural resistance to dust mites and allergens, and it has been valued for centuries not just for its beauty but for how genuinely good it feels to wear.
Cotton
There's a reason cotton has been the fabric of daily life across every culture for thousands of years. It's soft, breathable, hypoallergenic, and completely natural. It allows constant airflow, absorbs moisture without feeling damp, and softens beautifully over time. When sourced thoughtfully, cotton is one of the most versatile and comfortable fibers available for everyday wear.
Wool
Often misunderstood as strictly a cold-weather fabric, wool is actually temperature-regulating — it insulates when it's cold and breathes when it's warm. Merino wool in particular is fine, soft, and lightweight. Wool absorbs moisture as vapor before it becomes sweat, which means it stays dry and fresh far longer than synthetics. It's naturally antimicrobial and biodegradable.
"But Natural Fibers Are More Expensive"
They are, sometimes. And that's worth talking about honestly.
A linen top costs more than a polyester one. A silk blouse is an investment. But the math changes when you factor in how long they last, how much better they feel to wear every single day, and what you're not paying in terms of your health and the world around you.
Fast fashion's low prices are made possible by low-cost synthetic materials, high-volume production, and corners cut at every stage of the supply chain. You pay $18 for a top and you get exactly $18 worth of fabric, construction, and longevity.
We believe in making fewer, better choices. One linen top you love and wear for years is worth more — in every way that matters — than five polyester ones you cycle through in a season.
A Small Shift That Feels Like a Big One
We're not asking you to throw out your wardrobe. We're inviting you to start paying attention — to read the labels, to notice how different fabrics feel against your skin, to ask whether the "elevated" aesthetic of what you're buying is actually backed by elevated materials.
That's the whole idea behind Sunday Supply. Timeless pieces in fabrics that are worth wearing. Natural fibers that breathe, that soften, that last — because you shouldn't have to sacrifice quality for beauty, or beauty for quality.
You're too pretty for polyester. So is your wardrobe.
Explore our first collection of natural fiber essentials — crafted in silk and cotton for effortless everyday beauty.