The light sensitivity of paper is a well-known concern among conservators and art curators working in the field of graphic art. The micro-fading test (MFT) is gaining increasing recognition as a valuable tool for predicting the future color change of art objects resulting from light exposure. However, paper as a substrate has so far received limited attention in MFT research. This dissertation explores the application of MFT to investigate the light sensitivity of paper, with an emphasis on optimizing methodologies and comparing data from Xenon-based (Xe-MFT) and LED-based (LED-MFT) devices with other aging conditions. These included artificial aging in chamber and natural aging in three different exposure settings. In this regard, this study aims to fill a gap in the MFT community by providing a comprehensive comparative analysis between MFT results and real-world data. In this study, the instrumental error associated with MFT tests is quantified and mitigated, and the effects of including UV radiation in Xe-MFT tests are explored. Additionally, the study presents the first mapping and quantification of UV radiation at the measurement point through the development of a custom model. Another key focus was determining the Xe-MFT spot size and advocating for more standardized methodologies. Paper samples across four series – pre-industrial (A), industrial (B), contemporary (C), and chromophore-doped (D) – were studied in the research. Results revealed distinct trends influenced by compositional factors such as lignin, iron salts, and optical brightening agents (OBAs). The comparison between Xe-MFT and LED-MFT and real-world data indicated that LED-MFT more accurately replicated natural aging under LED illumination, while Xe-MFT aligned better with artificial chamber aging. This research advances the understanding of comparability of MFT and real-world data for the specific case of paper, providing insights to inform preservation strategies for paper-based cultural heritage.
Giulia Vannucci (Thu,) studied this question.