FDM 3D printing has also been used in optics to make diffuse optics and optic faceplates . Our group has also incorporated dichroic nanoparticles in a plastic filament for printing, for the first time, a dichroic object, in this case with an optical effect like the Lycurgus cup (Figure ). This paragraph is only a short introduction to the multiple possibilities of making your own composite material for 3D printing, and it is not meant to be exhaustive, as there are other niches where composite 3D printing material will shine. However, I thought that it was necessary to show at least some opportunities arising from not only designing objects with specific features, for example, with high surface area, or for mixing capabilities, but also from coupling them with unique, application-driven, composite materials made in the lab.