Polar fleece is used in jackets, hats, sweaters, sweatpants, cloth nappies (diapers), gym clothes, hoodies, blankets, and high-performance outdoor clothing. It can be made partially from recycled plastic bottles and is very light, soft, and easy to wash. Polar fleece can stretch more easily in one direction than in others.
Polar fleece originated in Massachusetts in 1979 when Malden Mills, (now Polartec LLC), and Patagonia developed Synchilla (synthetic chinchilla). It was a new, light, strong pile fabric meant to mimic—and in some ways surpass—wool. Company CEO Aaron Feuerstein intentionally declined to patent Polar fleece, allowing the material to be produced cheaply and widely by many vendors, leading to the material's quick and wide acceptance.
A lightweight, warm and soft fabric, fleece has some of wool's good qualities but weighs a fraction of the lightest available woolens. Polar fleece garments traditionally come in different thicknesses: micro, 100, 200, and 300, with 300 being the thickest and least flexible.
It is hydrophobic, holding less than 1% of its weight in water. It retains much of its insulating quality even when wet. It is machine washable and dries quickly. It is a good alternative to wool for those who are allergic or sensitive to wool. It can also be made out of recycled polyethylene terephthalate (PET) bottles, or even recycled fleece. Despite its fuzzy appearance and feel, it is not flammable, but instead melts when exposed to flame.
Regular polar fleece is not windproof and does not absorb moisture (although this is often seen as a benefit, per above). Fleece readily generates static electricity, which causes the accumulation of lint, dust, and pet hair. It is also susceptible to damage from high temperature washing, tumble drying, or ironing. Lower-quality polar fleece material is also prone to pilling.