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Stay Perfectly Warm or Cool, Whichever You Prefer (We Won't Judge)
Look, we're rather chuffed with this one. A proper merino baselayer that actually does what it promises without making you feel like you've wrapped yourself in a science experiment. This is the heavier version of our flagship seamless knit, engineered with sustainably sourced merino wool to keep you at precisely the right temperature, whether you're training hard or simply existing.
Why Choose Our Infrared Merino Baselayer Top
Intelligent Temperature Control: Cooling zones ensure you stay at the perfect temperature regardless of activity or environment. The fabric stores thermal energy 63 percent longer than standard fabrics and dries 65 percent faster when used as a baselayer.
Genuinely Flattering Fit: Expandable side and arm panels mean you get the ultimate fit without that awkward bunching situation. Flattering rib detail at neck and shoulders. Designed to hug the body comfortably without feeling restrictive.
Performance-Focused Benefits: Our infrared technology increases local blood circulation and tissue oxygenation by up to 20 percent. You'll experience enhanced cellular metabolism, accelerated recovery from physical exertion, and a 25 percent average reduction in pain naturally. The technology also reduces inflammation and provides an 80 percent average reduction in soft tissue injuries through muscle priming.
Breathable and Quick Drying: Move freely without overheating. The seamless construction means no irritating seams when you're pushing yourself.
Versatile Wear: Wear it solo during training or as a sophisticated layering piece when the weather turns. Lightweight enough for workouts yet warm enough for winter months.
Sun and Bacteria Protection: SPF35 plus rating and antimicrobial properties keep you protected without fussing.
Product Details
Fabric Composition: 100 percent Infracycle Merino Wool, sustainably sourced.
Sizing: Available in XS through XL. Model pictured wears size Small at 160cm/5 feet 3 inches. Our garments don't need to be tight against the skin for the infrared technology to work brilliantly, so we suggest fitting to your personal preference. If you prefer a looser fit, size up from the standard guide recommendations.
Care Instructions: Hand wash only. Do not tumble dry.
Recommended Use: For optimum results, wear for at least 30 minutes before exercise, during your workout, and for at least one hour after to maximise recovery benefits.
This is genuinely rather good. Rather good indeed.
SHIPPING + RETURNS
THE RATHER IMPORTANT BITS
This rather lovely piece ships directly from our brand partner - we work with independent brands who are absolutely brilliant and work frightfully hard to create beautiful things.
SHIPPING DESTINATIONS
Now, here's the thing - our wonderful brand partners ship to lots of different places, but not all of them can ship worldwide.
Some are brilliant at international shipping, others prefer to keep things closer to home.
At checkout, you'll see exactly where this particular brand can send your goodies.
We're terribly sorry, but shipping costs do vary rather wildly depending on where you are in the world. The exact figures pop up at checkout - no nasty surprises!
RETURNS
You have 14 days to return items.
Now, we absolutely adore our brand partners - they work incredibly hard and we do try to support them as much as we possibly can. So I'm rather afraid we have to pass the return postage costs back to you. Frightfully sorry about that!
🌍 PLEASE CHOOSE THOUGHTFULLY:
Our wonderful partners put their hearts into everything they make.
Ordering multiple sizes to try at home is rather hard on our planet and makes things jolly difficult for these brilliant independent creators.
When in doubt, do ask us first!
PAYMENT
We're frightfully modern and accept all the usual suspects:
Visa, Mastercard, American Express, PayPal, Apple Pay, Google Pay, and Shop Pay
SECURE AS HOUSES
Everything's properly encrypted and secure - your details are safer than the Crown Jewels!
All prices in lovely British pounds £ GBP, though international chaps will see converted prices.
Any payment pickle? We're here to help sort things out! Contact us
We Have Lots More Like This.........
Hello, we are Sostter....
Sostter began, as all good ideas do, with a lively conversation and a shared sense of frustration. Why had the world of independent design become so serious, so samey, so… beige? Where was the spark, the imagination, the sheer joy of discovering something that made you stop and stare?
We dreamt of a marketplace that celebrated difference — where curious minds could explore a world of independent brands, design-led makers, and thoughtful artisans. A space that felt exciting, human, and beautifully imperfect.
Today, Sostter brings together remarkable people and their creations — from London to Lausanne, Brooklyn to Berlin — uniting makers and discoverers through craftsmanship, creativity, and conscience. Every object tells a story, and every purchase supports an independent brand doing things differently.
This is just the beginning. But enough about us — step inside, explore our world, and see what catches your imagination.
Giving Back
We’re proud to support Sutton Night Watch, a grassroots UK charity making a real difference in the lives of those facing homelessness. Through regular donations of stock, supplies, and essentials, we back their mission to offer warmth, dignity, and practical help to anyone in need — right where it matters most.
Sell with us
Sostter partners with independent brands that intrigue, inspire, and bring something genuinely different to the world of fashion, design, and living.Join us!