A High-Performance Inner Layer that Prevents "Sweat Chill": The Innovation of "Dry Layer" by "finetrack" who Celebrates 20 Years

As temperatures drop, the excitement of winter sports rises. Skiing, snowboarding, ice skating... Many adults are likely to head out dressed in their favorite heavy outerwear to enjoy the extraordinary snowy world.

However, simply having a high-performance coat or jacket is not enough preparation. In fact, it is the inner layer that holds the key to comfort.

I spoke with Yukiko Tanaka, who is responsible for development at Finetrack, about the high-performance underwear "Dry Layer" that is gaining attention in the industry.

Revolutionary Concept of Wearing One Layer under Sweat-Absorbing Quick-Dry Wear

First, could you tell us about Finetrack? The brand started from a single-family house in Kobe back in January 2004, right?

It was founded as a new venture by veterans responsible for planning and development at major domestic outdoor manufacturers, along with enthusiasts who have practiced outdoor life for years.

The approach of linking the needs and seeds of "playmakers = creators" has been recognized by Hyogo Prefecture's management innovation plan, and they continue to focus on manufacturing with a commitment to Japanese-made products, emphasizing thorough safety.

The founder, Yotaro Kanayama, originally came from a major outdoor manufacturer, right?

Yes. He has loved mountaineering since childhood, and both his work and private life revolve around outdoor activities. He enjoys nature through climbing, canyoning, and river kayaking. That is why he felt dissatisfied that there weren't any truly comfortable clothes that satisfied him.

So, at the age of 54, he decided to start his own company. In pursuing a one-of-a-kind product he wanted to use himself, he established the motto, "Rather than following trends, I want to prioritize functionality that protects life."

The representative idea born from this experience and passion is the water-repellent underwear "Dry Layer," right?

It keeps the skin dry and protects body temperature. This is a revolutionary mesh underwear that you wear under sweat-absorbing quick-dry wear.

Until then, the common practice for mountaineering wear was the three-layering system (insulating underwear + insulating wear + waterproof wear), but Kanayama and the Finetrack staff faced the risk of "sweat chill" and believed that it was necessary to have "underwear that does not cool even if you sweat."

How Dry Layer Prevents "Sweat Chill"

Please tell us again about the risks of sweat chill in winter that we should be aware of.

When engaged in strenuous activity that causes sweat to flow, the body is kept warm. However, as sweat dries, heat is lost. Moreover, the soaked sweat-absorbing underwear requires a certain amount of time to dry. During that time, the wet underwear continues to touch the skin, lowering body temperature.

Additionally, when people feel cold, they expend energy to maintain body temperature. Thus, Dry Layer prevents sweat chill by quickly removing sweat from the skin, conserving unnecessary energy expenditure.

That is why, especially in winter sports, it is important to place Dry Layer as the innermost layer of the three-layering system.

Exactly. The fabric of Dry Layer, which is treated with a durable water-repellent finish, is difficult to absorb moisture, so even if the sweat-absorbing wear on top gets wet from sweat or rain, it's no problem. It consistently ensures heat retention and minimizes body temperature drops.

It sounds like magical underwear—could you explain how it works?

It features two main structures. The first is the uneven thread. The fibers that make up Dry Layer have deliberately uneven cross-sectional shapes in size and shape (only for Dry Layer Basic). By thoroughly applying water-repellent agents to the surface of these larger surface area threads, each thread successfully repels sweat and rain, enhancing durability during washing.

The second feature is the design of the mesh holes. In typical mesh fabric, several threads go through the holes. However, in Dry Layer's mesh holes, the threads traverse without crossing. This creates "sweat pathways," increasing the opportunity for the base layer worn on top to absorb sweat.

I see. I can imagine that a significant amount of effort went into creating such a groundbreaking mesh fabric.

The process involved making prototypes, conducting field tests, and repeatedly incorporating feedback. Everything from fabric development to manufacturing, water-repellent treatments, and sewing was unprecedented.

For instance, the thinness of the fabric is a result of trial and error. After many tests, we ultimately adopted a fabric thickness of approximately 0.4mm, which was initially deemed a failure for being “too thin.” It offers a very light wearing experience, coupled with a gentle stretch, making it comfortable even during intense activities.

Moreover, the aforementioned penetration mesh cannot be produced by the latest knitting machines. Therefore, we still carefully maintain traditional knitting machines, slowly and meticulously continuing to weave.

The commitment to Japanese manufacturing within Japan's brands also preserves the traditions of Japan's textile industry. It has been 20 years since the birth of Dry Layer, but what developments can we expect in the future?

I can't provide too many details, but we are continuing to develop fabrics that consider SDGs. Furthermore, Dry Layer has a significant number of female users, as women tend to have more concerns regarding coldness. Thus, we are considering expanding our product lineup and PR targeting female users. Please look forward to it!

The revolutionary underwear that was born in 2004 has also branched out into “Dry Layer Warm,” which enhances thermal performance in 2019, and “Dry Layer Cool,” featuring pleasant contact cooling in 2020.

In this context, finetrack has gained support from many professionals. It has garnered immense trust not only from athletes battling in harsh fields but also from mountain rescue teams and self-defense forces.

“Playmakers = Creators.” The free-thinking and essence-seeking abilities cultivated through play are transforming Japan’s winter into a more enjoyable and safer experience.