The present disclosure provides a filament for use in an extrusion-based additive manufacturing system made from or containing a propylene ethylene copolymer having: ethylene derived units content ranging from about 3.0 wt % to about 12.0 wt %, based upon the weight of the propylene ethylene copolymer; MFR L (Melt Flow Rate according to ISO 1133, condition L, at 230° C. and 2.16 kg load) from about 4 to about 20 g/10 min; and xylene solubles measured at 25° C. from about 3 wt % to about 30 wt %, based upon the weight of the propylene ethylene copolymer. The disclosure further provides an extrusion-based additive manufacturing system made from or containing the filament as well as 3D printed articles prepared from the system.