A DMM was preferred over, for example, a Si(111) monochromator, typically used for powder diffraction at synchrotron beamlines, because of its higher transmittance. The reduced 2θ resolution in the XRD data, which is the consequence of the lower energy resolution of the DMM relative to that of a double crystal monochromator (DCM), proved to be sufficient for the measurements performed in this study. After the energy selection, the 30-keV beam was focused on the paint multilayer fragment by means of an elliptical single-bounce capillary to a spot size of 15μm. A MarCCD area detector (2 k × 2 k, 80 μm pixel size) was positioned behind the sample, acquiring two-dimensional diffraction patterns. Additionally, a silicon drift detector, positioned at 90◦ with respect to the incoming beam, allowed the simultaneous registration of fluorescence spectra, thereby combining XRF tomography (element distributions in a virtual cross section) and XRD tomography (crystallographic phase distributions). Figure 2 summarizes the combined μ-XRF/XRD tomography setup as well as the pattern decomposition method explained earlier.