Paintings on marble from Herculaneum and Pompeii

This work is a new step in the research about the so-called "Monochromes on marbles". The ten slabs from Pompeii and Herculaneum are now preserved in the National Archaeological Museum in Naples. These marble pinakes were mostly set in walls of roman buildings with iron clamps. The scenes represent different subjects spanning from mythological to athletic ones. The "Monochromes", at a first sight, seem to be drawn only with the red colour, but actually the slabs show also green, yellow, brown and black colours, still visible to the naked eye. The paper presents the results obtained during the in-situ analytical campaign carried out at the museum by using a set of portable, non-invasive techniques on the ten slabs of white marble. The techniques used can be divided in two groups: 1) multispectral photographic techniques and 2) single spot analyses. In addition a Portable Optical Microscope was used for the documentation of each single spot analysed. Crossing the results obtained with both imaging techniques and single spot analyses, some new information about drawings, pigments and conservation history have been provided, contributing to deepen the knowledge of this rare kind of archaeological objects.