What is clean? That is a question we all answer differently. Some may think of a clean room when all clutter is hidden beneath the bed, hidden from sight. On the other hand, some others may not be able to fully relax unless the living room smells of flowers and chlorine vapours fill the bathroom.
Microfiber cloths are conquering households and the professional cleaning industry rapidly with names like 'Wonder Cloth' and 'All Purpose Cloth'. Originally, the chemical industry had other plans for the thin threads. In their search for a synthetic fiber for thermal clothing, they developed the microfiber during the mid-eighties. The fabric it was woven into felt nice because of its capability to absorb perspiration. Though soon a disadvantage arose; the material attracted dust and dirt. A Swedish manufacturer made a virtue of necessity by developing a cleaning cloth out of microfiber during the early nineties. In the first years after the development people were sceptic: another super cloth. A few years ago the product was discovered again. Thanks to improved techniques the microfiber now also appears in sportswear, mountaineering boots and furniture fabrics.  Microfibers have a diameter of less then 0,012 millimetres, about one hundred times thinner than a human hair. This thin synthetic thread is incredibly light; 10 kilometres of microfiber weighs less than one gramme. Synthetic fibers consist of polymers, which are long chains of linked molecules, comparable to a string of beads. The thread from which the microfiber are created, is 70 percent polyester. The other 30 percent is polyamide, a polymer better known as nylon. When the synthetic fibre is made into a cloth, it still is no wonder cloth. Microfibers are only created after chemical treatment or by exerting force on the cloth during the manufacturing process. By using chemicals, a powerful jet of water or by stretching the tissue, the connection between the polyamide and polyester is broken. The round fiber then falls apart into a star-shaped core of polyamide, which is then surrounded by wedge-like polyester fibers. A cross section of the fiber is comparable to a star, cut out of a paper circle. The triangular shaped paper pieces that remain represent the polyester fibers. The polyester part is the real microfiber, though the star-shaped polyamide core has its own function. Oil and fat easily attach to polyamide. When using a normal cloth, soap is needed to obtain the same effect; the soap serves as a solvent which converts the grease into minute drops, which the cloth then absorbs. Microfiber cloths help you clean fast, because they have an enormous surface; the cloth is in fact many times bigger than its visible dimensions. The reason for this are numerous triangle-shaped polyester fibers. A big cleaning surface means a high absorbing power; big cloths can simply absorb more dirt than small cloths. The fibers are situated closely together. The small areas between them pull up the dirty water by the capillary action. Capillary action is the way that fluid in a narrow area tends to crawl up the sides. This is clearly demonstrated by a glass of lemonade with a straw. In the straw the fluid level is higher than in the rest of the glass. Ordinary cloths also have some capillary action, though much less because of bigger pores.
A microfiber's sharp edges penetrate deep into the dirt, much further than a round fiber does. Microfibers grab dirt, round fibers often only stroke over. The material picks up dirt so well that rinsing by hand does not help much. Only a mechanical washing can make a dirty cloth really useful again. The fiber also has other advantages when it's dry. The dry cloth is statically charged by the rubbing movement. The positively charged cloth then attracts dust particles.
Research that was carried out by TNO (Dutch organization for Applied Scientific Research), by order of Vereniging Schoonmaak Research (Organization for Cleaning Research), shows that a microfiber cloth together with some tepid water cleans many stains much quicker than an ordinary cloth and a warm soapy liquid. Also, the research shows that an ordinary cloth doesn't always need soap. And although it is sufficient to only use water to clean with the microfiber cloth, together with cleaning products the microfiber cloth cleans many times better than conventional cleaning cloths.

German:

Mikrofaser ist eine Sammelbezeichnung für Fasern, deren Einzelfäden feiner als ein Denier sind. Ein paar Vergleiche, um eine Vorstellung zu vermitteln: Mikrofasern haben den halben Durchmesser von Seidefasern, ein Drittel des Durchmessers einer Baumwollfaser, ein Viertel des Durchmessers feiner Wollfasern und nur ein Hundertstel des Durchmessers eines menschlichen Haares.

Feine Seide zum Beispiel hat ungefähr 1,24 den (Denier). Eine Mikrofaser muss 0,9 den oder weniger haben, die meisten Mikrofasern liegen bei 0,5 bis 0,6 den. Noch dünnere Fasern (< 0,3 den) bezeichnet man als Supermikrofasern.

Weil Mikrofasern so fein sind, können viele von ihnen eng zusammengepackt werden. Diese Dichte führt zu anderen wünschenswerten Eigenschaften. Es werden viel mehr feine Fasern benötigt, um einen Faden zu bekommen, was zu einer größeren Fadenoberfläche führt. Mikrofaser-Textilien sind sehr resistent gegen Pilling.