A thin, broadly distributed layer of foreign material that changes the appearance, wetting, or feel of a glass surface.
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Meaning and boundaries
Film describes form, not composition. A film can be oily, soapy, polymeric, mineral-rich, or a corrosion product, and it is not necessarily removable by one cleaning method.
Why it matters in glass restoration
Films can create haze, streaking, water beading, poor adhesion, false inspection results, or uneven polishing behavior.
Related terms
References
- ASTM International — ASTM C813-20: Hydrophobic Contamination on Glass by Contact Angle Measurement
Publisher’s original source - U.S. Geological Survey — Hardness of Water
Publisher’s original source - Vitro Architectural Glass — TD-107: Residue on Glass
Publisher’s original source - Pilkington / NSG Group — Pilkington Activ: Technical Tips
Publisher’s original source