A good office mat should last years, without any damage, scratches, or scuffs. However, they can slowly wear down the fibers of the carpet beneath due to the weight. Carpets don't last forever, not even the Turkish and Persian rugs woven from wool with beautiful designs. Every carpet wears down over time. Mats may place additional pressure on this regular wear and tear, allowing the carpet under the mat to look different from the rest of the carpet over the years. I avoid this simply by rearranging my office every few months. I love decorating and setting new moods in my workspace. It keeps me productive and creative!