Evaluation of glass by observing light, a scene, or a target through the glazing.
GlassRenu · Educational illustration
Meaning and boundaries
It does not show every reflective coating defect or surface-height change and can be affected by background brightness and multiple glass plies.
Why it matters in glass restoration
It helps evaluate haze, clarity, transmitted distortion, scratches, inclusions, and the visual effect of restored areas.
Related terms
References
- National Glass Association — Guidelines on How to View Decorative Glazing Products
Publisher’s original source - ASTM International — ASTM C1376-21a: Pyrolytic and Vacuum Deposition Coatings on Flat Glass
Publisher’s original source - ASTM International — ASTM C1652/C1652M-21(2025): Measuring Optical Distortion Using Digital Photography of Grids
Publisher’s original source