Wicking is the same thing as “capillary action".
OK, capillary action sounds even more complicated, but it’s not too
complex. First, I will give you the summary, and then I will give
you a slightly more complicated explanation.
Simple definition of wicking: In regard to
clothing, wicking moves moisture away from the body to the outer
layer of the fabric so that it then has a better chance to evaporate
away. For cold weather activities, people often
layer clothing. The most inner
layer should be a wicking material. It would actually be good to
have all layers having a wicking ability.The purpose of
the inner layer is to draw the sweat away from the skin to the next
layers, which makes the wearer feel warmer and more comfortable. The
transfer of moisture happens due to capillary action, which we
have explained is sometimes called wicking. The fabrics used to draw
moisture away are called wicking materials. When moisture has moved
from the skin into (nonabsorbent) clothing, it has more surface area and
will evaporate faster.
Note: if you are wearing a few layers of clothing,
the moisture may become trapped between layers if some of the layers are
waterproof. It is important for the layer closest to your skin is
made of wicking material so that the moisture can at least move away
from the body.
More Complicated Explanation: Wiking or
capillarity is the ability of a liquid to flow in narrow spaces without
the assistance of, or even in opposition to, external forces like
gravity. The effect can be seen in the drawing up of liquids between the
hairs of a paint-brush, in a thin tube, in porous materials such as
paper and plaster, in some non-porous materials such as sand and
liquefied carbon fiber, or in a cell. It occurs because of
intermolecular forces between the liquid and surrounding solid surfaces.
If the diameter of the tube is sufficiently small, then the combination
of surface tension (which is caused by cohesion within the liquid) and
adhesive forces between the liquid and container wall act to lift the
Again, clothing is made with wicking fabrics to
help draw off liquid from the wearers body by capillary action.
Moisture wicking fabric is a kind of fabric that is
commonly used in workout clothing and sportswear because the material is
designed to pull moisture away from the skin. This will help keep
athletes at a more appropriate body temperature and comfort.
Polyester and other synthetic fibers have superior
wicking and therefore an ability to dry quickly. Polyester clothes
are naturally designed to bring sweat from the inner surface to the
outer surface, thus leaving the skin dry.
Polyester, a synthetic material (man-made) that has a peculiar
ability to pull moisture away from the skin to the exterior of the
clothing. The key to this is the material’s hydrophobic, or
‘water-hating,’ chemical quality within the microfibers of the fabric.
Essentially during exercise, the microfibers move sweat to drier areas,
i.e. from the skin to the exterior of the clothing where it can
evaporate more easily.
Cotton does not wick as well as polyester because
cotton “absorbs" moisture.