Background: Presented article summarizes the results of a broad-based survey on painting techniques used during the High and Late Gothic period in the Bohemian panel paintings located in the collections of the National Gallery in Prague. The work is focused on the specific use of yellow pigments -lead tin yellow type I and type II in the panel painting from the period around 1340-1550. In the scientific investigation supplementary microscopic and spectral analyses were made. A representative range of 57 micro-samples collected from the 36 panel paintings of the 21 Masters and their workshops was investigated by the methods of optical microscopy on polarizing microscope (OM). Molecular analysis of both types of yellow was performed using Raman micro-spectroscopy (RMS). The use of this technique was crucial for the nondestructive differentiation between each type of lead-tin yellow. Results: Thanks to the Raman spectroscopy it was possible for the first time to map the usage of lead tin yellow type I and II in such a broad range. Combination of the analytical techniques brought the knowledge about the morphology of the grains and variability of the use of the lead tin yellows in the Bohemian panel paintings. Conclusions: The contribution offers a systematic view on the outcomes and in a synoptic way consults the results of respective scientific methods. It clearly confirms both the temporally and locally specific use of both types of lead tin yellows. The presented facts are the results of interdisciplinary collaboration among the scientists and the art historian.

No abstract

No abstract

No abstract

The use of computed tomography (CT) for studying artwork has a long tradition in the restoration and care of collections in memory institutions. The result of the related tomographic reconstruction is a virtual spatial model in which we can examine the production technology, the internal structure, various damaged areas, and previous restoration interventions. The extension of standard CT to dual energy CT provides additional information to help distinguish materials with similar densities but different chemical compositions. As will be shown, pigment differences that appear very similar in optical light can be identified in this way. The differences found were confirmed by X-ray fluorescence and Raman spectroscopy analytical techniques. Current laboratory CT scanners make it possible to examine the layered structures of paintings and polychrome sculptures. In the case of wood panel paintings, however, we are faced with the common deformation of the panels. So, when examining the CT data, we can only see a small section of the paint layer, and it is difficult to examine the whole artwork in its entire context. This disadvantage can be solved by a virtual straightening of the panel, as will be demonstrated.