Polartec® Alpha® was invented because some things in life happen too fast to layer up or down. The U.S. Special Operations Forces (SOF) can think of a few, and for years there were no options on the market that could meet their specific needs — a breathable, quick-drying, and packable insulation for demanding start-stop activities.

So SOF approached Polartec​®​ with a brief to develop a versatile insulation technology that could remain comfortable through extreme temperature variations while operating in mountainous terrain. In other words, they wanted to eliminate the need to shed layers when things got hot in a combat zone or add them at rest. That's how the seeds were planted for the world's first Active Insulation.

The U.S. government makes an ideal partner when developing a new technology (see: GPS, the Internet, airbags, etc. ) because it can fund far better and more thorough testing than, well, anyone. Polartec Alpha came to be through extensive lab and field testing in extreme environments, including cold weather combat training in Kodiak, Alaska.

SOF prepares for fighting in miserable conditions and test clothing systems by walking into a river in spring or winter conditions with their entire PCU (Protective Combat Uniform) on, stay submerged for 15 minutes, then get out and walk the system dry. This is just one of the ways Alpha was tested, yielding scientific data and feedback for an in-depth report.​

Of all the Polartec​®​ fabrics tested by the U.S. Special Operations Forces' Evaluation team, Alpha received the highest marks. In 2012, the SOF Protective Combat Uniform Level 3A Jacket became standard issue for every Special Forces Operator, and it’s still in deployment today. This groundbreaking Alpha jacket replaces two to three layers, which reduces costs, saves weight in the field, and improves operational effectiveness. In short, Alpha simplifies dressing for cold weather start-stop activities.

The U.S. Special Forces called on the Science of Fabric to invent an entirely new category of performance fabrics. Before Polartec Alpha, Active Insulation simply didn't exist — but what exactly is Active Insulation, and how does Alpha achieve it?

Typical down and classic synthetic insulation are less formed, prone to migration, and can poke through lighter face fabrics. To keep these fibers in place, they must be sandwiched between high-density woven layers that create a vapor barrier. While such solutions will keep the wearer warm at rest, even minimal activity quickly results in sweat that then gets trapped, creating uncomfortable saturation. If a rupture occurs, you've got a real mess on your hands — especially in a combat zone where your position may have just been compromised by an explosion of bright batting.

Alpha is not a batting. Lofted fibers connect to a sturdy knit-lattice structure, creating a stable layer that allows for more air-permeable face and back fabrics. As the world’s foremost fabric finisher, Polartec was able to figure out how to brush this (nearly lacelike) open knit without ripping it apart.

The lattice shape permits a small amount of airflow that enhances breathability, so Alpha can be worn in a wider range of activities without the need to add or shed layers. Alpha's structural integrity also means it won't spill out in the unlikely event of a rupture or migrate into clusters that can create hot and cold spots.

In addition to unprecedented levels of breathability and moisture vapor transport, Polartec Alpha still insulates effectively while wet and offers dramatically faster dry times. This versatility means Alpha can be paired with pretty much any combination of facing or backing fabrics — or no fabric at all.

Polartec® Alpha® Direct insulation takes Alpha's features one step further with enhanced resiliency and durability. Alpha Direct's insulating fibers are uniquely shaped and sized to eliminate the need for a facing fabric. This visible technology offers direct warmth, increased breathability and compressibility, and even faster dry times, while reducing garment weight due to the lack of lining fabric.

Alpha's innovative Active Insulation enables hybrid product design that can combine performance attributes of base layers, insulation, and outerwear in a single garment. This renders the classic "layering system" approach to dressing for cold weather activity obsolete. Naturally, designers for categories across the consumer market have found new and surprising uses for this game-changing fabric technology.

For your convenience, we compiled a list of the finest uses of Polartec​®​ Alpha​®​ and Polartec​®Alpha​®​ Direct from brands in the cycling, outdoor, lifestyle, running, and tactical worlds who aren't afraid to rethink the traditional layering system.

Alpha's development with the U.S. Special Forces is one of our favorite technology origin stories because it reflects our history of staying on the cutting edge of fabric technology and demonstrates what we mean when we talk about the Science of Fabric. Before SOF came to Polartec​®​ to develop this product, it didn’t exist. They searched high and low, scoured tradeshows, but the exact design solution they needed — breathable, adaptable warmth in start-stop activities — wasn’t available.

The Science of Fabric brought SOF's brief to life, and Alpha is yet to have an equivalent competitor on the market. Alpha's structural integrity is its unique advantage, inspired by our generational experience as knitters. Other fabric companies have knocked off NeoShell, they’ve riffed on fleece, but thanks to Alpha's knit-lattice structure, the Active Insulation game is still all ours.

We hope this list helped narrow down the search for a new springtime insulator or inspired the next great Alpha design. Polartec Alpha offers the most comfort throughout the widest range of temperatures and activity levels, so its uses are boundless. As always, Polartec​®​ is ready to push the Science of Fabric forward and make the impossible possible.