1. Institute of Heritage Science, National Research Council (CNR ISPC), Via R. Cozzi 53, 20125 Milan, Italy
2. Collection Care Department, The National Archives (TNA), Bessant Drive, Kew TW9 4DU, U.K.
3. Department of Chemistry, University of Milan, Via C. Golgi 19, 20133 Milan, Italy
4. Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, UK Research and Innovation (UKRI), Harwell Campus, Harwell OX11 0QX, U.K.