Even when they have been cleaned, traffic lanes in synthetic carpeting can still look "beat", because over time and foot traffic, they become beat. Synthetic fibers, more than wool fibers, gradually lose their ability to stand up straight, so they reflect light at a different angle than fibers in less travelled areas that still have all or most of their original
ability to stand up straight. Due to all the squishing they receive under foot, they also become abraded (dull) so they appear less lustrous to the eye than fibers that are out of the traffic lane.
