Was not very pleased with the results of the traffic lanes at the dentist offiice i did today. the carpet is nylon and has been there roughly 3 to 5 yrs. never been cleaned as far as the owner knows. so i used zone perfect plus citri solv and then rinsed with an acid. they used those plastic mat in the office/reception area. so the 3x3 uncovered area showed up more. Im really disapointed on this one. Was wondering if the the threads may have some etch makings, causing it not to reflect like it used to. Any ideas. By the way the hall ways are 4 ft wide.