Telltale fragments Close examination of chips, labeled according to their blue, yellow, or red color, that once belonged to art on the Berlin Wall reveals brushstrokes, multiple layers, and the pigments used. Credit: Adapted from F. Armetta et al., 2024 Nondestructive techniques like Raman spectroscopy are often used to identify the molecular signatures of pigments, dyes, and other chemical compounds, but this usually requires bringing samples to the lab. Handheld Raman devices are used for case...