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Recurring to the scattering and quantum effects of nanostructures to improve the performance of a thermoelectric (TE) material has become common sense in current TE research. The ability to perform grain boundary engineering and thus learn how to decouple electrical and thermal transport effects is also crucial to the advancement of thermoelectric nanocomposites. However, the challenge is how to do this in a 3D bulk material, which is also the main carrier of the applied TE devices. The front cover article by Gothard et al. (pp. 157–162) presents an attempt to achieve this by mixing a nanoscale material (C60) in a bulk (3D) thermoelectric material, by two distinct techniques: ball milling and mixing of powders. Microstructures of the ball-milled and mixed bismuth telluride-fullerene nanocomposites, along with elemental maps of the ball-milled microstructure are presented in the cover graphics together with a plot of the total thermal conductivity vs. temperature for the 5% fullerene nanocomposites, as compared to the state of the art (SOA) ingot.