This dataset consists of micro-computed tomography (µCT) images of a multi-material cube test specimen additively manufactured using fused filament fabrication (FFF) and metal-filled filaments. The cube is composed of eight smaller cubes, alternating the materials. * __Outer Dimensions:__ 20 x 20 x 20 mm³ (with each individual cube measuring 10 x 10 x 10 mm³) * __Materials:__ colorFabb Steelfill and colorFabb Copperfill (PLA) * __FFF Machine:__ Flashforge Creator Pro 2 (refer to the included .gx file for printing parameters) * __µCT Scanner:__ Bruker SkyScan 1275   In the reconstructed cross-sectional CT images, the darker material represents the denser copper-filled filament. ### Acknowledgments * The project _“Computer tomograph for optomechatronic systems”_ was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Project number 432176896.