1. Department of Conservation and Restoration and LAQV‐REQUIMTE, NOVA School of Sciences and Technology NOVA University Lisbon Monte da Caparica 2829‐516 Portugal
2. “Nello Carrara” Institute of Applied Physics Italian National Research Council (IFAC‐CNR) Via Madonna del Piano 10 Sesto Fiorentino 50019 Italy
3. Institute for Photonics and Nanotechnologies Italian National Research Council (IFN‐CNR) Piazza Leonardo da Vinci 32 Milan 20133 Italy
4. Courtauld Institute of Art Somerset House London WC2R ORN UK
5. Centro Interuniversitário de História das Ciências e da Tecnologia, Faculdade de Ciências Universidade de Lisboa Campo Grande Lisbon 1749‐016 Portugal