Bunkier Sztuki Collection.
Case Variation

Since 2001, Leszek Sobocki has been painting portraits of Cracovians—people who are close to him spiritually, artistically, or intellectually. In his work, he strives not only to depict the physical appearance of his subjects but also to convey their emotions and state of mind. His art becomes a form of psychological analysis of the model. We decided to investigate what lies behind the extraordinary expressiveness of these paintings and how the artist achieves it through his choice of pigments. An important factor in selecting this particular work for analysis was its painterly qualities—its color scheme and composition. We chose a piece which, when scanned using Macro X-Ray Fluorescence (MA-XRF), would yield results that are both visually and scientifically interesting.

In the exhibition, alongside Nobel Laureate I by Leszek Sobocki, we present maps of elemental distribution that reveal the painting’s composition. MA-XRF scanning is a non-invasive, non-destructive analytical technique used to identify mineral pigments. During the process, the energy of the secondary X-Ray emission, characteristic of each atom, is measured after being excited by an X-Ray lamp from the measurement system. The resulting data visualizes the distribution of specific elements, with colour intensity reflecting their concentration in different areas. These elemental maps create new, unique images that offer fresh insights into the artwork.

This technique, primarily used in art conservation to study artistic techniques and materials, allows us to observe not only the materials used but also the artist’s working methods. The analysis of Nobel Laureate I identified elements such as calcium (Ca), iron (Fe), barium (Ba), zinc (Zn), cadmium (Cd), cobalt (Co), and titanium (Ti). Examining the individual maps, we can see that calcium is present in the underpainting/groundwork, while iron was used for the underpainting applied with broad brushstrokes, visible in the texture. Barium is commonly used as a filler in paints, increasing their mass and influencing texture. The presence of zinc is particularly noticeable, as the main white pigment used is zinc white, which the artist mixed with all other paints, benefiting from its subtle transparency. The painting also contains cadmium yellow (Cd), likely mixed with an organic green pigment. It seems that some areas of red are also organic, possibly madder root. Sobocki deliberately applied cobalt blue (Co) in selected areas of the skin tones, giving them a slightly cool shade. This effect is not immediately visible, as it is layered beneath titanium white (Ti). This type of white, denser and less transparent than zinc white, was intentionally used for the stronger highlights on the surface. The dark contours visible on some of the maps result from the X-Ray signal being blocked by heavier elements such as titanium, preventing it from penetrating deeper layers.

The use of modern analytical tools allows us to view artworks in a new way. We can gain deeper insights into the artist’s technique and uncover the stages of the painting’s creation.