Filtration media, whether they are woven or non-woven, are constructed from either natural or man-made fibres.

The development of synthetic fibres, such as polyester, polypropylene, nylon, aramid, rayon, viscose and polyethylene, has all but eliminated the use of natural fibre media in liquid filtration. When we select a media for a specific application, its "fibre content" can be critical due to the fibres' ability to withstand specific chemical and thermal environments.