Octa Fleece is a breathable fleece with excellent moisture absorption and quick drying properties.

Fleece is a versatile thermal garment. It's warm, soft, lightweight, and durable. Its all-around versatility makes it the standard for thermal wear.

However, some of the fleece's features are known to be incompatible with high-intensity outdoor activities. For example, its high thermal insulation can lead to poor heat dissipation, causing overheating. Simply put, for situations where the amount of exercise varies little, such as when using it in town, you can focus only on its thermal properties.
However, when engaging in intense exercise that raises body temperature, the body's ability to retain heat becomes a major issue. As a result, high-intensity exercise can easily create hot spots that retain heat in certain areas, leading to excessive sweating.

What's more, many fleeces have a slow wicking rate, meaning they're not good at absorbing sweat and passing it on to the outer layer. In fact, some fleeces trap the sweat they absorb within the fabric, causing it to become damp with sweat vapor instead of being released into the air, ultimately resulting in chills.

Because of these characteristics, it has been considered undesirable to use fleece in high-intensity activities in low temperatures, such as hiking up a backcountry ski slope, due to the sweat management issues.

But think back to the comfort of a fleece on a winter morning, the feeling of being wrapped up in a blanket. The appeal is in how quickly it warms you up, from the moment you put it on. It doesn't feel tight anywhere on your body, and it's stress-free, even when you're driving or stopping at a cafe on your way back from a hike in the mountains. Its lightness and warmth give you the ultimate feeling of satisfaction.

So, the TETON BROS. crew thought.
We wondered if it was possible to create clothing that could withstand high-intensity exercise while still retaining the appeal of fleece.
Of course, as mentioned above, fleece is not suitable for hard winter activities. We know this, which is why we have created a variety of active insulation products. Fleece cannot achieve what we are looking for. However, fleece is just too appealing in terms of comfort.

"Yes, it sounds tempting, but there's no fleece like that. OK, let's make one."

Thus began TETON BROS.'s specialty, the process of creating something that doesn't exist in the world.
They reexamined the properties of every material they could get their hands on, involved the production team in considering manufacturing methods, and spoke to guides and testers to find out how they could bring the garment they envisioned into the real world.

The result was the use of Octa, a high-performance material that has become the most familiar to TETON BROS. in recent years. Octa is a hollow fiber with eight radial projections. Structurally, it can be thought of as a thread resembling a fish cake with eight ribs.

Octa is a yarn that controls air. The space inside the yarn does not move. Therefore, it can maintain stable heat retention regardless of the situation. In contrast, the space created by the intricate intertwining of the fibers contains a large amount of air. This acts as heat retention when stationary, and when moving, it is physically moved, replacing the surrounding air and contributing to heat dissipation. Octa's very existence functions perfectly as active insulation.

Octa Fleece is made by brushing fabric using Octa to create fleece.
The first thing that strikes you when you pick it up is how light it is. The outer surface is not brushed, so it feels smooth like a sweatshirt, but it looks heavy. However, when you hold it in your hand, you're surprised. It feels airy and so light that it's hard to comprehend for a moment how light it is.

Top) Soft, dense recycled polyester outer layer. Bottom) Brushed Octa knit backing. Sweat and moisture are quickly wicked away from the outer layer.

What's more, it feels exceptionally soft and comfortable when you put it on.
The moderate stretch puts no stress on the body, so you can practically feel like you're not even wearing it, yet you can still fully enjoy the unique warmth and quick-warming heat retention of fleece.

Additionally, the product we tested has the same off-center zipper style as the old Afton Hoody. With a balaclava-style hood and slightly longer sleeves, every part of the jacket fits snugly against the body, providing a comfortable fit.

The center zipper is offset so that the zipper does not overlap and does not touch the mouth or nose. The hood fits snugly to the head and can also be used as a balaclava.

It also has a pocket with a micro zipper on the abdomen. The size is perfect for hand warmers, and there's nothing to complain about when it comes to keeping warm. You'll once again realize that fleece clothing can boost your sense of well-being in the winter.

The zippered pockets on both sides and thumb holes keep your hands warm, making it useful in cold weather.

While these benefits of conventional fleece have certainly been improved, the problem remains in terms of sweat management and heat dissipation. So, we tested the fleece at various exercise intensities, including hiking, cycling, fishing, and mountain running (the temperature at Mt. Asahi was such that the first snow fell a few days after the test), to check its sweat absorption, drying speed, and cooling effect from sweat. A detailed description of the results would require 10,000 words, but we can summarise them in one line.

No discomfort. No problems. Actually, I was surprised. Good. Awesome.

In fact, sweat dripping onto the inner fleece surface is absorbed as soon as it hits the ground, spreading out until it soaks into the outer fabric. The sweat absorption is the result of Octa's complex intertwining properties and capillary action, but this is the first time I've seen fleece that absorbs sweat so quickly.

A few drops of water were dropped onto the inner Octa brushed surface. The water was quickly absorbed and spread across the outer surface.

What's more, it also excels at wicking away heat. I tested it almost entirely without wearing a shell over the Octa Fleece, and while I did feel a slight heat on my back when hiking or cycling, there was none of the heat buildup that typically occurs with fleece. While I did feel some hot spots on my back and sides during mountain running, that's understandable considering the high intensity of the exercise involved. What surprised me more was how well it absorbed sweat and dried quickly, even when worn directly over the ELV1000.

This would mean it could be used in the backcountry in winter, although it would depend on the user's constitution, temperature, exercise intensity, etc. A garment has now been released that can be used as a "mid-layer with moderate warmth" in fields where fleece was previously considered out of the question.

Of course, it should be noted here that while Octa Fleece is designed for fairly active situations as a fleece, it is by no means "active insulation" as defined by TETON BROS.
For people who sweat a lot, for situations where high-intensity exercise is expected in extremely low temperatures, or for activities that involve frequent stop-and-go movements, we recommend choosing products that further enhance their functionality as active insulation by effectively using Octa or VIVO.

The appeal of Octa Fleece is that it offers the same high level of warmth and comfort in static situations as conventional fleece, but also the broader range of its application, allowing it to cover much more active situations. In that sense, it seems like a new category called "semi-active insulation" could be created for Octa Fleece, a fleece that has never existed before.

The soft, comfortable fit, moderate stretch, and cutting ensure that it does not cause any stress.
The new TETON BROS. brand logo is embroidered on the chest.

The Octa Fleece fabric has a hard face similar to sweatshirt fabric, made from recycled polyester on the outer side. During field testing, I sometimes wore it over the Tsurugi Lite Jacket, and the smooth sliding between the shell meant that it didn't lose comfort even when layered. This subtle outer fabric treatment directly contributes to ease of movement and improves its usability as insulation, making it a highly rated mid-layer garment.

Octa Fleece is a versatile fabric that can be used as insulation, a softshell in mild weather, relaxing at camp or as a layer for travel.
By improving breathability and heat dissipation, as well as sweat absorption and quick drying, this fleece has pioneered a new realm. Experience the breathability of this fabric for yourself.