Figure 6From: Winsor & Newton original handbooks: a surface-enhanced Raman scattering (SERS) and Raman spectral database of dyes from modern watercolor pigmentsSERS analysis of madder lake-based pigments. (a) SERS spectrum of reference madder lake upon HF treatment compared to examples of SERS spectra obtained from Winsor & Newton madder lake-based pigments (λexc = 488 nm): (b) rose madder 20th century edition, (c) rose madder 19th century edition, (d) Rubens’ madder 20th century edition, (e) Rubens’ madder 19th century edition, and (f) warm sepia 20th century edition.Back to article page