FDM (Fused Deposition Modelling) 3D printing emerged in the last few years as one of the most promising additive manufacturing techniques for fast prototyping. In this work, this technique is used to fabricate UHF (Ultra High Frequency) RFID (Radiofrequency Identification) flexible tag antennas, using a plastic-based conductive filament with copper inclusions, called Electrifi. A comparison with other prototypes with similar shape but fabricated through different and already investigated techniques [1] has been performed in terms of ease of use, processing time, cost, tag sensitivity, radiation pattern, and impedance. More specifically, 3D-printing technology for RFID tag fabrication is compared with inkjet printing, screen printing, wax-based deposition, and cutting plotter. The conductive properties of the antennas realized with the Electrifi filament, as expected, are lower than those of the antennas realized with the other techniques. Nevertheless, a slight degradation in terms of tag performances, is balanced by the extremely high versatility of the fabrication technique. Moreover, the capability to easily fabricate a fully 3D printable antenna, together with the possibility to print complex and not only planar geometries, pave the way to interesting and meaningful future developments