This article presents the design and manufacture of microwave planar devices using additive techniques. The substrate design process, based on a low-cost 3D printer and standard filament with different additive options, is described. The designed substrates have been characterized to obtain their dielectric properties in the range of 0.1 GHz to 4 GHz. Finally, to check the possibility of using the manufactured substrates, two stepped impedance filters have been designed in the RF range. Some of the options offered by the additive techniques in the substrates design have used. The designed filters have been simulated and measured with good results, which demonstrates the possibility of using low-cost 3D printers in the RF circuit design process.