this is also confirmed by the absorption tomogram (Fig. 1). For each of the eight layers, one representative crystalline constituent was selected and ten cross-sectional profiles were extracted from the XRD tomogram at different positions. The average thickness and average interface width are given in Table 3 for XRD tomograms reconstructed with the FBP and MLEM method. The calculated average thickness is the same for both methods within the observed standard deviation. Comparison with values obtained from the absorption tomogram in Fig. 1, representing a cross section of the paint fragment at a different height than the XRD tomograms, reveals differences in average thickness that are larger than the standard deviation. This indicates an inhomogeneous layer deposition, especially for layers 3 to 5, which contain talc and aluminum flakes.