We present, evaluate and discuss the viability of commercial 3D printer filaments for use in terahertz 3D printing applications. This is achieved in a combined approach, analysing optical and mechanical properties in conjunction with the filaments' overall printability. We analyse 18 common and exotic filaments including: acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), nylon, polyethylene terephthalate (PET), high impact polystyrene (HIPS), polypropylene (PP), polycarbonate (PC) and polyvinyl alcohol (PVA) with their corresponding coploymer blends and modifications. Optically, samples are characterized in the 0.1-1 THz frequency range via time domain spectroscopy. Prints were produced on a Makerbot Replicator 2X experimental 3D printer. Interestingly, optical properties are shown to remain consistent despite mechanical modifications made to the filament.