The Function of Wickable Fabric

Wicking fabrics are modern technical fabrics which draw moisture (sweat) away from the body. They are made of high-tech polyester, which unlike cotton, absorbs very little water. Cotton will absorb 7% of its weight in water, polyester only 0.4%. Cotton will therefore hang onto your sweat, making your garment heavy and unpleasantly clammy. Wicking polyester has a special cross-section and a large surface area, which picks up moisture and carries it away from your body, spreading it out, to evaporate easily on the outside of the fabric. So you stay cool and dry.

Breathability

Some people will refer to wicking fabrics as being breathable – that is, they let air in and sweat out, allowing the skin to breathe and cool itself. The lightweight material doesn’t weigh on your body like wool or cotton, and it's easy to carry.

Breathable showerproof and waterproof fabrics have tiny pores in the fabric, larger than water vapour molecules (so these can get out) but much smaller than drops of rain (so these can’t get in). 

Regulates Body Temperature

Wickable material draws moisture away from the skin and accelerates evaporation. If you sweat under a jacket and it's cold outside, moisture near your skin may cause a drop in body temperature, which can lead to hypothermia. Excessive sweat can also cause dehydration. By keeping moisture away from the skin, wickable materials help the body maintain an appropriate temperature.

The Science

The two properties normally used to predict wicking performance in a fabric are capillary pressure and permeability. Capillary pressure is the main force responsible for the movement of moisture along or through a fabric, where the force of the surface tension between the liquid and the walls of a narrow gap or pore overcome the forces between the molecules of the liquid, moving it into empty gaps until the forces even out. Permeability is the measure of a fabric’s ability to transport moisture through itself, and is determined by a combination of sizes of spaces within it and the connections between the spaces.

Maintenance

Wickable fabric is made from low-maintenance materials and can be spot-cleaned. Launder when needed, but air dry the fabric so heat from a dryer doesn't damage or melt the synthetic fibers. Since most the water will simply bead off the material, the time needed to air dry is significantly less than water-absorbing materials. Simply shake the garment to remove excess water droplets and hang it to dry.