Why a Short-Sleeve Merino Feels Comfortable—even When It’s Cold
Being recommended a short-sleeve T-shirt in the middle of February may feel a little unusual.
But that’s only true if you’re using a “cotton T-shirt” as the baseline. Once the material changes, the role of clothing changes too. Here, we’ll整理 this from both sides—numbers and real-life comfort— to explain why short-sleeve merino can work in winter.
What the numbers say: cotton vs. merino wool
First, let’s look at commonly cited reference values to understand the differences between cotton and merino wool. (These numbers are simply helpful clues for everyday material choices—rough understanding is enough.)
| Category | Cotton | Merino wool |
|---|---|---|
| Fiber diameter | Approx. 20–30 μm | Approx. 18.5 μm or less (reference for Super 100’s wool) |
| Moisture regain | Approx. 8% (reference) | Approx. 15–18% (reference) |
| Odor retention | Body oils tend to remain on the surface | Odor molecules are more readily absorbed into the fiber structure |
*These values are general references. Comfort varies depending on yarn, knit structure, and construction.
Why “short sleeves in winter” can make sense
Merino wool is less about “warming you up,” and more about stabilizing your body temperature.
When you sweat, it helps release excess heat. When you’re about to feel chilled, it gently retains warmth. That regulation happens in the layer closest to your skin. That’s why, sometimes, refining your base layer feels more comfortable than simply adding more layers.
In winter, you often sweat more than expected indoors or while commuting. Long-sleeve innerwear can feel stuffy in those situations. A short-sleeve merino layer avoids trapping unnecessary heat and helps reduce the stress of temperature swings.
Wool T-shirts differ depending on their intended use
Many wool T-shirts are also made by sports brands. Because they prioritize lightness and fast drying, they’re often designed to be thin. That’s fine if you wear them as an inner layer, but when worn on their own, transparency can sometimes be an issue.
At C-one, we design with the assumption that you’ll wear it as a standalone piece in the city. We prioritize fabric weight and opacity. Being able to wear it without layering makes it easier to use in daily life.
For everyday wear, color matters too. C-one keeps a foundation of versatile basics, while still offering a range that’s easy to style.
We also avoid silhouettes that are too narrowly defined by “the scene.” Crew-neck tees that work under a jacket, polo shirts designed for ease of movement— rather than “this shape because it’s wool,” we choose by working backward from how you actually wear it.
Because it’s built for harsh conditions, daily life feels easier
Merino wool has long been used in demanding settings— mountaineering, long travel days, and other tough conditions.
Less chill even when you sweat. Adaptability to temperature differences. Comfort even after consecutive wears. These are performances that matter most in harsh environments.
At C-one, we understand those properties and translate them into silhouettes and balance that fit everyday life. Not for special occasions, but for pieces you can use naturally—without forcing it—within your daily routine.
As a result, it becomes a T-shirt you can wear on workdays, on weekends, while traveling, or in light active moments. Because the material is designed for tough conditions, in daily life it feels like “margin”—a quiet ease. That’s how we think about C-one’s wool T-shirts.
Start by experiencing it in short sleeves
Comfortable on its own in summer. Quietly supportive as an inner layer in winter.
Because it works across seasons, you’ll feel the difference in daily life.