3D printing filaments are solid strand thermoplastic feedstock for use in fused deposition construction of three-dimensional models using 3D printers. Filaments are differentiated by diameter, weight, tensile strength, flex strength, and density with common plastic formulations including ABS, PLA, PET, PA, PC, PS, PVA and TPU. Popular diameters are 1.75 mm, 2.85 mm, and 3.00 mm and are available in a wide range of solid and translucent colors.