Fig. 8

Reflection mid-FTIR analysis of the Alchemy binding media. a Spectra collected on cadmium yellow paints appearing as thick (yellow1) and diluted (yellow2, M03,) applications (see Additional file 3 for point location); b spectra showing the signals of a long chain aliphatic hydrocarbon characteristic of some yellow paints and the viridian-based green (green1); c spectra showing the signals of zinc carboxylates and zinc oxalates characteristic of the manganese violet, phthalo blue (blue1) and ZnO-anatase based white (white1); d spectra showing the lipidic signals particularly broadened by additional organic compounds characteristic of the red Cd-based (red2), phthalo green (green2), rutile-anhydrite (white2) and some black paints; e spectra showing strong signals from the inorganic constituents of the paint and a further organic component in addition to the lipid-one, these profile are characteristic of the hematite-based deep red, ultramarine blue (blue2) and orange CdSSe-based paints; f spectra from glossy black poured paints (black lines) and black matt paints (grey lines) (see Additional file 4) compared with the spectrum from a reference film of alkyd resin (red line)