Mirrors provide both functional and aesthetic performance in the interior design for today's homes, office buildings, schools, medical and institutional facilities. In addition to the function of providing reflected images, mirrors are being used to move natural light further into buildings and enhance the openness of rooms. Proper cleaning procedures must be followed to ensure the long-term performance of mirrors. This document provides suggest procedures for cleaning flat glass mirrors. This document was originally published in January 2005, updated in 2012 and republished in July 2019.