Salvator Mundi: an investigation of the painting\u2019s materials and techniques

Thomas J Tague,Nica Gutman Rieppi,Beth A Price,Peng Wang,Ken Sutherland,Ting Wang,Andrew P Lins,Richard Newman

doi:10.1186/s40494-020-00382-3

Abstract

Before the start of its restoration in 2007, the Salvator Mundi was thought to be one of a number of copies of a long-lost Leonardo da Vinci painting, depicting Christ giving a blessing with his right hand while holding a crystal orb in his left. During the restoration treatment, a scientific examination of the painting was carried out to elucidate the painting’s materials and techniques. Microscopic sampling of the painting was necessarily limited, and nine out of ten samples were prepared and analyzed as cross-sections. A number of analytical methods were employed selectively, including stereomicroscopy, visible and fluorescent light microscopy, scanning electron microscopy with energy dispersive spectroscopy, Raman microspectroscopy, Fourier transform infrared microspectroscopy in transmission mode and with attenuated total reflection. The pigments characterized were lead white, vermilion, red iron oxide earth, red lake, natural ultramarine, lead–tin yellow, umber, and charcoal, carbon and bone blacks. Manganese-containing soda-lime glass was detected in the ground, imprimitura and paint layers, and a walnut oil medium was identified by pyrolysis gas chromatography-mass spectrometry. Cross-section studies revealed aspects of the painting’s stratigraphy: a size layer, white ground and off-white imprimitura, followed by a complex sequence of paint layers applied by the artist to achieve sophisticated visual effects.

Highlights

In 2017, the painting Salvator Mundi was sold as a rediscovered work by Leonardo da Vinci by Christie’s auction house (Fig. 1)
Analyses were undertaken using a complement of instrumental techniques: visible and fluorescent light microscopy (VLM and Visible and fluorescent light microscopy (FLM)), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), Raman microspectroscopy, Fourier transform infrared microspectroscopy (MFTIR), FTIR with attenuated total reflection (ATR-FTIR), and pyrolysis gas chromatography-mass spectrometry (Py-GCMS)
In 2011, in preparation for the exhibition ‘Leonardo da Vinci: Painter at the Court of Milan’ at the National Gallery, London, Visible and fluorescent light microscopy (VLM and FLM) Samples for cross-sections were embedded in Bio-Plastic® polyester-polystyrene resin (Ward’s Natural Science), cured, and polished with 4000 to 12,000 grade MicroMesh abrasives

Summary

Introduction

In 2017, the painting Salvator Mundi was sold as a rediscovered work by Leonardo da Vinci by Christie’s auction house (Fig. 1). Cross-section analysis combined with stereomicroscopic examinations and IRR [2] provided information about the paint stratigraphy of the background of the composition This part of the painting appears to have been executed with an initial, thin black paint application (the ‘lay-in’) that was applied directly over the imprimitura and subsequently built up with multiple warm-toned brown and black paint layers. The surviving remnants of the background paint, revealed after the cleaning of the painting, were uniformly dark and exhibited a similar warm black color, suggesting that the background may have been even in tone and hue overall [2] This complex sequence of layers in the background can be seen in cross-section (Fig. 4). The glass may have served a drying function and to impart a translucent quality to the final paint surface and depth to the painted shadows

Methods

Results

Conclusion