Fig. 6
From: Disclosing Jackson Pollock’s palette in Alchemy (1947) by non-invasive spectroscopies

Details of the visible image and key spectral features of paints denoted as blue1 and blue2. a UV–Vis-NIR spectrum and b Raman spectrum (λexc = 785 nm) representative of blue1 compared with the corresponding reference spectra of a phthalocyanine blue; c UV–Vis-NIR spectrum and d Raman spectrum (λexc = 785 nm) representative of blue2 compared with the corresponding reference spectra of ultramarine blue