Looking at old paintings with new eyes - chemical imaging useful for art historians and art conservators

X-ray radiography (XRR) and Infra-red reflectography (IRR) are two methods traditionally employed by musea world-wide for non-destructive analysis of paintings. There may be several reasons why a painting in subjected to this type of analysis:

  • art-historians may want to know more about the past of the paintings: how was it created? what changes were made to in during its (long) history? is something hidden below the surface?
  • art-dealers or owners of the artwork may questions about its authenticity: can objective indications be found to strengthen the link between a work of art and a (famous) painter or between series of paintings by the same artist ?
  • art-conservators may want to obtain information on the material aspects of a painting: which artists’ materials were used? which specific combination of pigments, dyes and binding media was employed to obtain a specific optical effect? which of these materials in their original conditions and which ones have degraded?

As an improved version of X-ray radiography, since 2007, the chemical imaging method of macroscopic X-ray fluorescence (MA-XRF) was developed. A mobile scanning instrument was developed that allows to examine the paintings in the gallery or museum collection they belong to.

MA-XRF has several advantages compared to XRR, the most important ones being:
(a) it produces a series of element-specific images that allow to map the distribution of the pigments used by the artist either at or just below the surface,
(b) the contrast in these elemental maps does not only reflect the distribution of lead white as in the case of XRR but may also reveal many other pigments.

In this presentation, the usefulness of MA-XRF to answer relevant questions of different nature from art-historian, art-dealers and art-conservators will discussed by means of a series of case studies. Imaging analyses of paintings from different historical paintings by famous Flemish, Dutch and Italian 15-17th century artists such as Memling, Caravaggio, Rubens and Rembrandt will be presented next to studies of more modern (20th century) paintings by Van Gogh, Magritte and Pollock.