Polar Fleece

Polar fleece is knit entirely from polyester fiber and finished with a deep, plush pile on both the face and back, with no cotton content and no brushed-one-side construction like sweatshirt fleece. Weights typically run 200-400 grams per square meter, roughly 6-12 oz, with heavier weights like 300 gsm showing up in outdoor jackets and lighter weights in blankets and vest linings.

Because polyester melts at relatively low heat and the pile is thick and uneven, this is a fabric where a heat press is a real risk. Press a plastisol transfer or vinyl at a typical 300-320°F dwell temperature and you can flatten the pile permanently, or worse, glaze and scorch the fiber. That's why embroidery dominates decoration on polar fleece jackets, vests, and blanket-style throws — the needle works through the pile without any heat involved at all.

If a customer insists on a printed look for a polar fleece garment, look at low-temperature vinyl or a patch sewn or heat-set at reduced time and temperature rather than a standard plastisol press, and always test on a scrap swatch first.

Buyers often confuse polar fleece with sweatshirt fleece because both get called "fleece" casually. Sweatshirt fleece is a cotton/poly knit with one smooth, printable face; polar fleece is 100% polyester with pile on both sides and no smooth face to print on at all.