Polartec Explained
In brief: Polartec is a US maker of high-performance fabrics, best known for inventing modern synthetic fleece. Its range spans lightweight breathable fleece, warm high-loft pile, and active insulation built for stop-start activity. Polartec fabrics are engineered for warmth without bulk, fast drying and breathability, and many are made using recycled materials. The name appears on outdoor and lifestyle garments from a wide range of premium brands.
What is Polartec?
Polartec is a fabric technology company, not a clothing brand. It develops and manufactures performance textiles that other brands then use in their garments, which is why you see the Polartec name on jackets and mid-layers from many different labels. The company grew out of Malden Mills, the American mill that created the first modern synthetic fleece in the early 1980s, and the Polartec brand name was introduced in 1991. Today the range covers a broad family of fabrics, from feather-light breathable fleece to warm insulating pile, each designed for a specific balance of warmth, weight, breathability and durability.
How Polartec fleece works
Polartec fleece is a knitted synthetic fabric, usually polyester, with a raised pile that traps air close to the body. Because the warmth comes from trapped air rather than the fibre itself, fleece delivers a lot of insulation for very little weight, and it keeps much of that warmth even when damp because synthetic fibres absorb very little water. It also dries quickly and breathes well, releasing excess heat and moisture during activity rather than leaving you clammy. This combination of light warmth, fast drying and breathability is what made fleece such a breakthrough over heavy wool layers, and it remains the everyday workhorse of the outdoor mid-layer.
The main Polartec fabric families
Polartec organises its fabrics into distinct families for different jobs. The core fleece range comes in graded weights, broadly light, mid and heavy, so you can match the warmth to the conditions. Thermal Pro is a higher-loft fleece offering more warmth and texture. High Loft uses a deep, lofted pile to trap more air for cold-weather warmth at low weight. Power Stretch is a close-fitting stretch fabric aimed at base and mid layers. And Polartec Alpha is an active insulation, developed originally with the US military, that breathes far better than traditional puffy insulation, making it ideal for high-output activity where you do not want to overheat.
Polartec Alpha and active insulation
Polartec Alpha deserves a mention of its own because it solves a specific problem. Traditional insulation keeps you warm when you are still, but can leave you sweaty and overheated once you start moving. Alpha is a lofted insulation built into a more open, breathable structure, so it dumps excess heat and moisture during activity while still keeping you warm when you slow down. It was developed for special forces who needed insulation that worked across stop-start missions, and it has since become popular in active outdoor jackets for exactly that reason. If you run hot or are constantly switching between effort and rest, active insulation like Alpha is often more comfortable than a conventional puffy layer.
Sustainability and recycled materials
Polartec has put significant effort into reducing the environmental footprint of its fabrics. Many fleece and insulation styles are now made using recycled content, including fibres made from post-consumer plastic bottles, and the company has reported recycling billions of bottles into fabric over the years. It has also worked to address fibre shedding, a known issue with synthetic fleece, through fabrics designed to reduce microfibre loss in the wash. For shoppers who want performance with a lighter environmental impact, looking for recycled Polartec fabrics is a practical way to get both.
Polartec at OD's Designer Clothing
At OD's Designer Clothing we stock garments built with Polartec fabrics across our outdoor and lifestyle ranges, from breathable fleece mid-layers to warmer lofted styles. Because Polartec sits inside garments from many premium brands, it is one of the most reliable signals of genuine performance you can look for on a label. We offer next-day delivery and free click and collect, and customers in the North West can visit our St Helens store to feel the weight and warmth of different Polartec fabrics in person.