Fig. 7From: Shades of blue: non-invasive spectroscopic investigations of Maya blue pigments. From laboratory mock-ups to Mesoamerican codicesUV–Vis reflectance and FT-IR spectra collected on real cases in comparison with reference standard samples (a Type 1, b Type 2, c Type 3, d Type 4). Spectra are vertically translated for clarity (P1: palygorskite-based Maya blue containing 1 wt% indigo; P03: palygorskite-based Maya blue containing 0.3 wt% indigo; S03: sepiolite-based Maya blue containing 0.3 wt% indigo)Back to article page