title: Exploring a Hidden Painting Below the Surface of René Magritte's Le Portrait.
abstract: Two state-of-the-art methods for non-invasive visualization of subsurface (or overpainted) pictorial layers present in painted works of art are employed to study Le portrait, painted by Belgian artist René Magritte in 1935. X-ray radiography, a commonly used method for the nondestructive inspection of paintings, had revealed the presence of an underlying figurative composition, part of an earlier Magritte painting entitled La pose enchantée (1927) which originally depicted two full length nude female figures with exaggerated facial features. On the one hand, macroscopic X-ray fluorescence analysis (MA-XRF), a method capable of providing information on the distribution of the key chemical elements present in many artists' pigments, was employed. The ability of the X-rays to penetrate the upper layer of paint enabled the imaging of the facial features of the female figure and provided information on Magritte's palette for both surface and hidden composition. On the other hand, visible and near infrared hyperspectral imaging spectroscopies in transmission mode were also used, especially in the area of the table cloth in order to look through the upper representation and reveal the pictorial layer(s) below. MA-XRF provided elemental information on the pigment distributions in both the final painting and the prior whereas the transmission mode provided information related to preparatory sketches as well as revealing differences between the paints used in both compositions. These results illustrate very well the manner in which the two imaging methods complement each other, both in the sense of providing different types of information on the nature and presence of paint components/pigments and in the sense of being optimally suited to easily penetrate through different types of overpaint.
authors.affiliation: AXES Research Group, Department of Chemistry, University of Antwerp, Antwerp, Belgium.
authors.forename: Geert
authors.initials: G
authors.lastname: Van der Snickt
authors.affiliation: The Museum of Modern Art, New York, USA.
authors.forename: Ana
authors.initials: A
authors.lastname: Martins
authors.affiliation: National Gallery of Art, Washington, DC, USA.
authors.forename: John
authors.initials: J
authors.lastname: Delaney
authors.affiliation: AXES Research Group, Department of Chemistry, University of Antwerp, Antwerp, Belgium koen.janssens@uantwerpen.be.
authors.forename: Koen
authors.initials: K
authors.lastname: Janssens
authors.affiliation: Night Vision and Electronic Sensors Directorate, Fort Belvoir, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Zeibel
authors.affiliation: The Museum of Modern Art, New York, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Duffy
authors.affiliation: The Museum of Modern Art, New York, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: McGlinchey
authors.affiliation: Department of Materials Science, Delft University of Technology, Delft, The Netherlands.
authors.forename: Birgit
authors.initials: B
authors.lastname: Van Driel
authors.affiliation: Department of Materials Science, Delft University of Technology, Delft, The Netherlands.
authors.forename: Joris
authors.initials: J
authors.lastname: Dik
keywords: Hidden painting; Hyperspectral imaging; La pose enchantée; Le portrait; MA-XRF; Macroscopic X-ray fluorescence; Magritte; Near-infrared imaging; SWIR; Short-wavelength infrared; Vis-NIR; Visible near-infrared