Fig. 9From: Organic colorants based on lac dye and brazilwood as markers for a chronology and geography of medieval scriptoria: a chemometrics approachBrazilwood paints, excitation and emission spectra representative for BW 1 group, Ajuda Songbook f. 59); BW 2 group, IL 42 f. 113; BW 3 group, ms 24 f. 60; and brazilein 5 × 10–5 M in MeOH:H2O (70:30, v/v) with Al3+ (× 1000) at pH 3.2, applied on filter paperBack to article page