Overpainted masterpieces revealed
July 31, 2008 All artists suffer for their work, very few become successful and sadly, even fewer artists become successful in their own lifetime. Given the price of canvas, many paintings were painted a second time, and many famous works of art still conceal previous works by the same artist. Now a new technique based on synchrotron radiation-induced X-ray fluorescence spectroscopy, is unveiling the paintings that were underneath in full colour and will greatly facilitate the study of other 'over painted' works of art in the future. The new technique was recently applied for the first time to the painting “Patch of Grass” by Vincent van Gogh, revealing a portrait of a woman underneath.
Until now, the technique usually used to reveal concealed layers of paintings has been conventional X-ray radiography, which has its limitations.
An international research team, including members from Delft University of Technology (The Netherlands) and the University of Antwerp (Belgium), has successfully applied this technique for the first time to the painting entitled Patch of Grass by Vincent van Gogh.
Beyond suffering for his art, the world’s best-known Post-Impressionist painter Vincent Van Gogh battled mental illness most of his life. Though he produced many famous paintings, he is best known for being eulogised by Don McLean in the song Vincent and for cutting off his ear as a sign of remorse after threatening fellow impressionist and friend Paul Gaugin with a razor.
Prodigiously talented, Van Gogh was not widely appreciated in his lifetime and once famously said, “as a suffering creature, I cannot do without something greater than I - something that is my life - the power to create.”
Indeed, Van Gogh did not decide to become an artist until he was 27 years of age, and committed suicide at 37, hence he spent most of his life as an artist in dire poverty and regularly repainted previous works of art - experts estimate about one third of his early paintings conceal other compositions under them.
The analysis of the painting 'Patch of Grass' by Vincent Van Gogh by means of an advanced form of non-destructive X-ray analysis reveals in unprecedented detail the original portrait, also by Van Gogh, over which the landscape was painted.
The new technique, based on synchrotron radiation induced X-ray fluorescence spectroscopy, reveals this type of hidden painting. The techniques usually used to reveal concealed layers of paintings, such as conventional X-ray radiography, have their limitations.
Together with experts from the Deutsches Elektronen-Synchrotron in Hamburg and the Kröller-Müller Museum, TU Delft materials expert and art historian Dr Joris Dik, and University of Antwerp chemistry professor Koen Janssens therefore chose to adopt a different approach. The painting is subjected to an X-ray bundle from a synchrotron radiation source, and the fluorescence of the layers of paint is measured.
This technique has the major advantage that the measured fluorescence is specific to each chemical element. Each type of atom (e.g. lead or mercury) and also individual paint pigments can therefore be charted individually. The benefit of using synchrotron radiation is that the upper layers of paint distort the measurements to a lesser degree. Moreover, the speed of measurement is high, which allows relatively large areas to be visualised.
Patch of Grass, was painted by Van Gogh in Paris in 1887 and is owned by the Kröller-Müller Museum. Previous research had already discovered the vague outline of a head behind the painting. It was scanned at the synchrotron radiation source DORIS at Deutsches Elektronen-Synchrotron DESY in Hamburg using an intense but very small X-ray bundle. Over the course of two days, the area covering the image of a woman’s head was scanned, measuring 17.5 x 17.5 cm.
The measurements enabled researchers to reconstruct the concealed painting in unparalleled detail. In particular the combination of the distribution of the elements mercury and antimony (from specific paint pigments) provided a 'colour photo' of the portrait which had been painted over.
The reconstruction enables art historians to understand the evolution of Van Gogh’s work better. The applied technique is expected to pave the way for research into many other concealed paintings.