Complementary MA‐XRF and μ‐Raman results on two Leonardo da Vinci drawings

Abstract

In 2018 all of Leonardo's drawings and manuscripts belonging to the Biblioteca Reale di Torino were moved to ICRCPAL for a complete scientific characterisation in preparation for the celebrations of the 500th anniversary of the artist's death. Except for the famous Autoritratto that was already studied twice in this manner (2012, 2015), the other drawings and documents had never been subjected to scientific investigations. This paper reports the results of the non‐destructive analysis of two drawings: Studi di gambe virili and Autoritratto. The use of three complementary techniques, namely macro‐X Ray Fluorescence (MA‐XRF), μ‐Raman spectroscopy and Atomic Force Microscopy (AFM), that have different penetration into the material, allowed for the complete chemical characterisation of the artworks. The analyses evidenced the artist's versatility and his mastery in the use of metal points, even unusual ones, such as the pure copper‐point described in literature but never previously revealed in Leonardo's drawings and, to the knowledge of the authors, also in other artists of the 15th century. MA‐XRF also showed the presence of pentimenti in the Studi di gambe virili and highlighted that the Autoritratto was drawn without a metal point preparatory sketch. AFM topographies also revealed that the Autoritratto urgently requires chemical stabilisation. The data collected underline the need to reconsider and reassess the historic‐artistic descriptions of the drawings and that further investigation of other works by Leonardo is necessary to obtain more information supported by scientific studies on the artist's techniques and materials.

Unveiling the Invisible in Uffizi Gallery’s Drawing 8P by Leonardo with Non-Invasive Optical Techniques

“…For instance, art history investigations on Leonardo da Vinci's drawings carried out in the past two decades have successfully integrated analytical measurements to identify constituting materials, delineate the artist's modus operandi, and characterize material deterioration over time [20][21][22]. Suffice to mention Leonardo's drawings belonging to the Biblioteca Reale in Turin, which were recently analyzed with macro X-ray Fluorescence (MA-XRF), μ-Raman spectroscopy, and atomic force microscopy (AFM) to identify their constituting materials and assess their state of conservation [23,24]. This line of research clearly points to the need for further integration of scientific methods to gain a thorough understanding of Leonardo's creative process.…”

Application of Macro X-ray Fluorescence Fast Mapping to Thickness Estimation of Layered Pigments

“…The state-of-the-art MA-XRF instrumentation is represented by raster scanning, i.e., mapping acquisition mode, being a time-and space-ordered collection of spectra [36]. MA-XRF is typically adopted for elemental distribution characterization [37][38][39][40][41], and also combined with several other techniques [42,43] and specific data handling [44]. Indeed, even though there are works exploiting X-ray as radiation to perform stratigraphic studies [27,[45][46][47][48][49][50][51], MA-XRF has never been devoted to the determination of layer thickness.…”

Atomic spectrometry update: review of advances in X-ray fluorescence spectrometry and its special applications

“…A multi-method approach is often used in cultural heritage applications to elucidate the objects under investigation such as drawings, manuscripts and paintings. Bicchieri et al 96 reported the results of the non-destructive analysis of two drawings: Studi di gambe virili and Autoritratto . The use of three complementary techniques (macroXRF spectrometry, μRaman spectroscopy and AFM) with different penetration capabilities gave a complete chemical characterisation of the artworks.…”