Spectral- and Image-Based Metrics for Evaluating Cleaning Tests on Unvarnished Painted Surfaces
Source abstract
Abstract
Despite advances in conservation–restoration treatments, most surface cleaning tests are subjectively evaluated. Scores according to qualitative criteria are employed to assess results, but these can vary by user and context. This paper presents a range of cleaning efficacy and homogeneity evaluation metrics for appraising cleaning trials, which minimise user bias by measuring quantifiable changes in the appearance and characteristic spectral properties of surfaces. The metrics are based on various imaging techniques (optical imaging by photography using visible light (VIS); spectral imaging in the visible-to-near-infrared (VNIR) and shortwave infrared (SWIR) ranges; chemical imaging by Fourier transform infrared (FTIR) spectral mapping in the mid-infrared (MIR) range; and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX) element mapping). They are complemented by appearance measurements (glossimetry and colourimetry). As a case study showcasing the low-cost to high-end metrics, agar gel spray cleaning tests on exposed ground and unvarnished oil paint mock-ups are reported. The evaluation metrics indicated that spraying agar (prepared with citric acid in ammonium hydroxide) at a surface-tailored pH was as a safe candidate for efficacious and homogenous soiling removal on water-sensitive oil paint and protein-bound ground. Further research is required to identify a gel-based cleaning system for oil-bound grounds.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Cultural Heritage Materials Analysis · Industrial Vision Systems and Defect Detection · Thermography and Photoacoustic Techniques
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Conservation Studies, University of Oslo, 0164 Oslo, Norway
Cultural History Museum, University of Oslo, 0130 Oslo, Norway
Department of Analytical Chemistry, University of the Basque Country UPV/EHU, 01006 Vitoria-Gasteiz, Spain
Department of Art Technology, Swiss Institute for Art Research (SIK-ISEA), 8008 Zurich, Switzerland
Haute École Art Conservation-Restoration (HE-Arc CR), Haute École Spécialisée de Suisse Occidentale (HES-SO), 2000 Neuchâtel, Switzerland
Laboratory of Technologies for Heritage Materials, University of Neuchâtel, 2000 Neuchâtel, Switzerland
Funding
Horizon 2020 research and innovation programme · Spanish Ministry of Universities · MCIU/AEI/10.13039/501100011033
References (100+)
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