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 suggested procedures for cleaning flat glass mirrors. The Technical Services Division of the National Glass Association (NGA) has produced this Glass Technical Paper solely for informational purposes. This Paper was developed by dedicated member volunteers and subject matter experts. The original version of this document was published in 2005. This version of the document was updated and published in February 2024.