The need for higher and higher performances of automotive and aerospace structures, and the parallel request for their lightening, are the reason why the conventional productive processes, characterized by a considerable amount of castable materials, are being progressively abandoned in favour of innovative technologies, which are usually referred to as rapid prototyping. This new way of designing and realizing components has its fundamentals on the massive use of 3D printing machines, which allow to build-up, by depositing material, geometries more complex than ever before starting from a model previously generated by Computer-Aided Design (CAD) tools. Emerged in 1980s as a revolutionary technology based on a laser-induced photo-polymerization process, rapid prototyping has progressively evolved into a sophisticated process known as Additive Manufacturing, which allows to produce free-form metal objects with intricate lattice and honeycomb features, from which the final product can be eventually derived.