A small, documented trial of a proposed cleaning or restoration method performed before broader treatment.
GlassRenu · Educational illustration
Meaning and boundaries
A successful test patch shows results only for the tested material, condition, method, operator, settings, and evaluation period.
Why it matters in glass restoration
It helps select the least aggressive effective method and reveals coating loss, scratching, haze, distortion, residue, or adjacent-material risk.
Related terms
References
- U.S. National Park Service — Preservation Matters: Stained Glass
Publisher’s original source - U.S. General Services Administration — Cleaning Historic Masonry
Publisher’s original source - Getty Conservation Institute — Twentieth-Century Building Materials: History and Conservation
Publisher’s original source