Semi-worked thermoplastic filaments used for 3D printing; Semi-worked PLA (polylactic acid) filaments for use in 3D printing; Semi-worked ABS (acrylonitrile butadiene styrene) filaments for use in 3D printing; Semi-worked ABS filaments for use in 3D printing; Semi-worked PLA filaments for use in 3D printing; Plastic filaments for 3D printing