X-ray analysis reveals overpainted fascist symbols
Left: The painting depicts a corner of Munich’s Odeonsplatz, with the Bavarian flag flying over the square. X-ray fluorescence analysis shows where areas have been overpainted with titanium white. Right: False-colour representation of the reconstructed painting featuring the memorial and the Nazi flag. © npj Heritage Science (2026) DOI: 10.1038/s40494-026-02577-6
Erich Mercker was a successful painter during the Nazi era and in the years that followed. After 1945, he covered up Nazi symbols in at least one of his paintings. With an interdisciplinary team, physicist Dr Ioanna Mantouvalou reports on this study in the Nature Journal Heritage Science.
Erich Mercker (1891–1973), a painter from Munich, was quite successful in his day. Between 1933 and 1945, he painted some works containing Nazi symbolism, including "Die Stätte des 9. November", which depicts the Feldherrnhalle monument in Munich commemorating the NSDAP's failed coup in 1923. After the war, Mercker, like many other German artists, simply continued his career.
Mercker also continued to paint the motif “Die Stätte des 9. November”, but without Nazi symbols and under alternative titles such as “Feldherrnhalle” or “München am Odeonsplatz”. He retained the same perspective, but omitted the soldiers and replaced the Nazi flag with a blue-and-white Bavarian one. This motif was discovered by the producer and filmmaker Dr Thomas Schuhbauer in his parents’ home. It had been given to them as a wedding present in 1966. As in the post-war version, the image shows the Bavarian flag and neither soldiers nor wreaths are depicted. However, the upper part of the monument is still visible. This strongly suggests that the painting dates from the Nazi era, as the monument was destroyed immediately after the war ended. Furthermore, reddish traces of paint are visible on the edge of the flag.
Non-destructive analysis
Thomas Schuhbauer contacted the HZB and began collaborating with Dr Ioanna Mantouvalou, a physicist who works in the SyncLab research group at TU Berlin and HZB. Dr Mantouvalou is an expert in X-ray fluorescence spectroscopy (XRF). This method enables the identification of elements in materials without damaging them. It can also be used to examine deeper layers, i.e. a few millimetres below the surface of a paint sample.
The XRF analysis clearly shows that parts of the original painting have been covered up to hide Nazi symbols. Notably, a red Nazi flag lies beneath the blue-and-white Bavarian flag. The wreaths on the monument, the soldiers, and the two raised arms of passers-by were also painted over. Oil paints containing significant amounts of titanium white were used for the overpainting. This pigment does not appear anywhere else in the painting, yet a tube of oil paint labelled 'Titanium White 10103 Schmincke' was found among Mercker's paint tubes.
Further evidence suggests that Mercker revised this painting himself, albeit either in haste or without attention to detail. In the Nature journal Heritage Science, the authors point out that many artists were hardly criticised for their collaboration during the Nazi era until well into the 1960s. The painting is now in the collection of the Munich Documentation Centre for the History of National Socialism.
'This collaboration was very exciting,' says Mantouvalou. ‘We had very different areas of expertise and backgrounds.’ For example, Professor Patrick Jung, an art historian, has written several books on Erich Mercker; Thomas Schuhbauer included this personal story in a documentary film about the legends of the German “Wirtschaftswunder”; and Magnus Bauer, Erich Mercker’s great-nephew, contributed important insights through his knowledge of the family history. ‘We had a wonderful experience, partly because we realised just how much of a barrier technical jargon can be. We had to get really creative to make sure we actually understood each other.’