Fleece vs Polartec Alpha

Fleece is a soft, napped fabric commonly made from knitted polyester and used for jackets, blankets, hats, and other insulating products. Modern synthetic fleece was developed by Malden Mills in the late twentieth century as a lightweight, quick-drying alternative to wool. Its raised pile traps air for warmth, but the fabric generally offers limited wind resistance unless combined with an addition...

Polartec Alpha is a synthetic active-insulation textile developed by Polartec in response to requirements from United States special operations forces. Unlike conventional insulation designed mainly to trap still air, its open and air-permeable construction allows heat and moisture to escape more readily during sustained movement. It is used in outdoor and military clothing for people who need war...