3D printing of composite materials appears to be an innovative way to control microwave properties of materials. Indeed, intrinsic properties are linked to the composition of composites but extrinsic properties (effective permittivity) can be managed by the shape and the control of porosity. Moreover, multi-materials 3D printing makes it possible to combine different materials so that to enlarge the available range of microwave properties. In this paper, it will be shown that the control of 3D printed materials can be complex but that design possibilities are almost endless. The spatial evolution and wide attainable range of microwave properties by using multi-materials honeycomb cells will be discussed and illustrated by the design, fabrication and characterization of a thin X-Ku band microwave absorber