UMID-PCH · Understanding Moisture-Induced Degradation in Painted Cultural Heritage

Europe’s cultural heritage holds an exceptional wealth of painted artworks that are increasingly at risk due to the inevitable effects of climate change. Fluctuations in humidity and accidental water exposure accelerate chemical and mechanical damage, leading to fading colours, weakened binders, and cracking. While previous research has often focused on the behaviour of wooden panels or canvas supports, the paint layers themselves remain poorly understood. Current models usually treat them as uniform solids, ignoring layer heterogeneity, porosity, and cracks, which significantly impact the diffusion of water into paintings.The UMID-PCH project will fill this gap by studying how water, both as vapor and liquid, interacts with painted structures. Laboratory samples will be created with traditional and modern painting techniques (egg tempera, oil, and acrylic) and artificially aged to reproduce realistic surfaces and crack patterns. Their response to humidity changes will be monitored using advanced magnetic resonance techniques (NMR) that allow to follow water transport. Selected historical artworks will also be studied to connect laboratory results with real conservation problems.Based on these insights, the project will develop a 2D numerical model of water diffusion in multilayered paintings, explicitly including cracks, porosity, and stratigraphy. This model will be made accessible to both scientists and conservators, providing a practical tool to predict the effects of different climates and conservation strategies.By linking advanced science with real-world conservation, UMID-PCH will generate new knowledge and tools to better protect painted heritage against the growing challenges of climate change.