Infrared spectroscopy based photodamage prediction model and assessment tool for paper and silk artifacts

Paper and silk artifacts are highly sensitive to photochemical damage during museum exhibitions. This study employs Fourier-transform infrared spectroscopy to establish crystallinity (C) and oxidation index (OI) as molecular-level photodamage indicators. Through accelerated aging experiments using the D55 standard illuminant and nine narrow-band light sources, the coupled influences of intensity (I), exposure time (t), relative spectral power distribution (S(λ)), and material relative spectral responsivity (P(λ)) were systematically quantified. A multi-parameter photodamage prediction model was established and validated, demonstrating high accuracy with mean absolute percentage errors of 8.37% for silk and 27.78% for paper. By integrating substrate degradation with color change models of 21 traditional pigments, a comprehensive predictive framework and risk-assessment software were developed. This research provides a quantitative tool for evaluating photodamage risk from museum light sources, supporting preventive conservation of paper- and silk-based artifacts.