Shop #1 Bestseller
The Signature Undershirt
Model wears a size S.
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Meet our #1 best seller.
This OG undershirt is the ultimate base-layer for every outfit. No more sweat-stains or deodorant marks – stay fresh and feel clean all day with this game-changer. With 250,000+ sold worldwide, The Signature Undershirt is the real deal.
Details
TECHNOLOGY
- Absorbent 100% Contemporary Cotton underarm shields that wick away sweat and odor
- Guaranteed to stop 100% of sweat stains
- Lightweight, 4-way stretch, comfortable and breathable
- Unmatched luxury and softness of our staple fabric
STYLE
- Reversible neckline: choose between scoop or jewel neck
- Seamless sleeves with a raw edge for an invisible look under outer layers
- The ultimate essential base layer
Fit
- Slim fit for an invisible base layer
- Order your regular size for the perfect, snug fit, or size up for a more relaxed look
- Hip length with short sleeves
Fabric & Care
FABRIC
- 90% Thermo-regulating, MODAL™ for ultra light weight softness, breathability, and keeping you cool and dry
- 10% LYCRA® for optimal stretch and comfort
- Made with shrink-resistant, fade-proof materials for long-lasting wear
- Responsibly knit and dyed in Canada
Discover more about our fabric here.
CARE
- Machine wash cold, tumble dry low
- Wash with like colors
Size Guide
Hear Why Women Swear By Numi
Shop Best Selling Sweat-Proof Undershirts
Discover The Best-Selling Sweat-Proof Undershirts That Actually Work
Why It’s Called a Wardrobe Game-Changer.
Because it keeps you polished, confident, and worry-free — with built-in protection so light, it feels like wearing nothing at all.
1. Built-In Sweat Shield
Pulls moisture away from your skin and prevents it from reaching your clothes — with no plastic layer, ever.
2. Breathable Modal Fabric
With a buttery soft feel and 4-way stretch, you’ll stay cool and comfortable all day long.
3. Clothing-Saving Design
Protects silks, sweaters, and blouses — helping your wardrobe (and your wallet) last longer.
NUMI Base layers
New Year. Same Wardrobe. More Wears.
One layer. Fewer washes. Lower cost per wear.
Product FAQs
Frequently Asked Questions
Why do I need an undershirt?
Undershirts are essential for women, providing a sweat-proof barrier to prevent visible sweat stains on outer clothing. Secondly, undershirts keep you dry and comfortable all day long, instilling the confidence in your wardrobe. They also extend the life of outerwear by reducing the need for frequent washing.
What makes Numi undershirts sweat-proof?
Our sweat-proof undershirts feature a Contemporary Cotton underarm shield, designed to wick and absorb moisture and prevent sweat stains from showing on your clothes. And by crafting the body of our undershirts from a TENCEL™ fabric to help regulate your body temperature, we guarantee all-day comfort.
How do I find the right size?
Find your perfect fit! Check our sizing guide on the product page, along with a handy sizing quiz to help you discover the right size for you. If you need personalized assistance, chat with us (bottom left corner) or email customercare@wearnumi.com.
How do I wear an undershirt?
Our undershirts are designed to be invisible under your clothes. They fit perfectly under your favourite blouses, sweaters and blazers to stop sweat stains and keep your clothes clean longer.
