On the use of hand-held X-ray fluorescence spectroscopy coupled to Monte Carlo simulations for the depth assessment of painted objects: The case study of a sixteenth-century illuminated printed book

This paper presents the application of an established XRF-MC (X-ray fluorescence-Monte Carlo) protocol to evaluate for the first time the thickness of pictorial layers in illuminated manuscripts. A previously investigated, sixteenth-century book printed in Paris (BPE, Inc. 438) was chosen as the case study: multiple analysis spots were scanned in selected areas (painted and unpainted) with p-XRF (hand-held XRF); later, the obtained spectra were compared against Monte Carlo simulations. Two pathways of MC simulations emerged: a three-layer model for the painted areas (stratigraphic sequence, from outer to inner: pictorial layer–underdrawing–parchment) and a two-layer model for the unpainted areas (underdrawing–parchment). Also, the calculated thickness of each simulated layer was compared against the thickness of micro-samples from Inc. 438. The results proved the protocol to provide quantitative compositional and stratigraphic data, yet with limitations. Results encourage the future research to elaborate a protocol.