Deterioration of a mirror's reflective or protective coating beginning at or near an edge, often visible as darkening, spotting, loss of reflectance, or creeping damage.
GlassRenu · Educational illustration
Meaning and boundaries
It is not a surface scratch or deposit on the front glass and cannot be polished away from the viewing surface.
Why it matters in glass restoration
Wet restoration, aggressive cleaner, contaminated gloves, or prolonged liquid contact at edges can worsen an existing or vulnerable mirror system.
Related terms
References
- ASTM International — C1503 — Standard Specification for Silvered Flat Glass Mirror
Publisher’s original source - National Glass Association — Proper Procedures for Cleaning Flat Glass Mirrors
Publisher’s original source - National Glass Association — Proper Procedures for Fabrication of Flat Glass Mirrors
Publisher’s original source