As indicated in the previous posts in this series, MoMA paintings conservators and conservation scientists have been studying five Magritte paintings for the past two years in preparation for Magritte: The Mystery of the Ordinary, 1926–1938.
There’s literally more than meets the eye in Magritte’s The Portrait (1935), as confirmed by a recent X-ray of the painting that exposed another painting hidden underneath. As outlined in a previous post, this hidden image corresponds to a section of The Enchanted Pose from 1927, also by Magritte, presumed lost since the early 1930s.
The Portrait is placed on an easel in front of the Bruker M6 Jetstream XRF scanner. The scanning took approximately 48 hours for a final resolution of a 0.5 mm.
Aside from the X-ray image, the only visual record of the painting underneath is a black-and-white photograph published in the Magritte catalogue raisonné. Little can be inferred about the artist’s palette from these two pieces of information so we decided to learn more about the colors Magritte used by turning to X-ray fluorescence (XRF) mapping to help identify the pigments.
Non-invasive XRF analysis has been used for decades now in cultural heritage science but always restricted to small areas. With advancements of the technique and fast computers, we can now collect millions of spectra in order to map an entire painting. The method is not equally sensitive to all pigments but many—like iron oxide, chrome yellow, and lead white, to name only a few—can be nicely identified. We knew that XRF scanning would help us determine the make-up of The Enchanted Pose with unprecedented detail and shed some light on the artist’s palette. What we didn’t know was how helpful it would be at revealing information about his technique and his approach to painting.
Joris Dik from the Delft University of Technology and Koen Janssens from the University of Antwerp originally developed the first mobile XRF scanner and granted MoMA a three-month loan of their instrument to examine a selection of paintings in the collection, including The Portrait and other Magritte paintings, right before the opening of the current Magritte exhibition.
XRF analysis simultaneously identifies and maps the chemical elements present in the paints. The distribution map of lead for example is very similar to the X-ray image, minus the stretcher since the information is collected from the front of the painting and not from the back. Cracks, canvas weave, and large brushstrokes in the top layer background and the female figure in the under painting are distinctly reproduced. The face of the woman appears in higher contrast indicating that the bottle (but also its shadow and the shadow of the plate) were painted first and right on top of The Enchanted Pose.
Lead distribution map (highlights correspond to a higher density of this particular element)
The iron distribution map shows that the element is present in both paintings, possibly as a earth brown in the dark shades of the flesh tones, mixed with lead white to paint the table, as Prussian blue in the blue section of the top painting, and possibly in the bottle outline and shadows (or alternatively Mars black). On the other hand, the apparent absence of an iron-based pigment in the woman’s hair indicates that it is painted in a color different than brown.
Iron distribution map
The distribution map for chromium reveals that the element is present in the sky of The Enchanted Pose. Chromium is somewhat unusual in the composition of blue paints but we found the same blue in most of the Magritte paintings from this time period that we were able to scan.
Chromium distribution map
Based on the list of all the chemical elements we identified (phosphorous, potassium, calcium, chromium, iron, zinc, cadmium, lead, and mercury) and their spatial distribution on the painting, we can start putting together a list of pigments for both The Enchanted Pose (red and/or brown earth, lead white, and vermillion) and The Portrait (ochre, bone black, possibly cadmium yellow, as well as Prussian blue and/or Mars black). Further analysis is underway to confirm the identity of the pigments and to further clarify the source of some of the elements to obtain the complete palette composition. In the end, we hope to have an accurate idea of the colors in The Enchanted Pose, giving us a fuller picture of this “lost” painting.
