A thermoplastic molding composition for 3D printing, comprising components A, B and C: A: 40 to 100 wt% of at least one polymer A having an average molar mass Mw of 150 000 to 360 000 g/mol, selected from the group consisting of: standard polystyrene, impact-resistant polystyrene (HIPS), styrene-acrylonitrile copolymers, α-methylstyrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, styrene-phenylmaleimide copolymers, styrene-methyl methacrylate copolymers, styrene-acrylonitrile-maleic anhydride copolymers, styrene-acrylonitrile-phenylmaleimide copolymers, α-methylstyrene-acrylonitrile-methyl methacrylate copolymers, α-methylstyrene-acrylonitrile-tert-butyl methacrylate copolymers, and styrene-acrylonitrile-tert-butyl methacrylate copolymers, where, in the high-impact polystyrene comprising polystyrene and diene rubber, the diene rubber fraction is 5 to 12 wt% and the polystyrene fraction is 88 to 95 wt% and the sum thereof makes 100 wt%; B: 0 to 60 wt% of one or more further polymers B selected from: polycarbonates, polyamides, poly(meth)acrylates and polyesters and vinylaromatic-diene copolymers, C: 0 to 50 wt% of customary additives and auxiliaries, the fractions of A, B and C being based in each case on the overall molding composition and the sum thereof making 100 wt%, characterized in that the viscosity (measured to ISO 11443) of the molding composition at shear rates of 1 to 10 1/s and at temperatures of 250°C is not higher than 1×10 5 Pa*s and the melt volume rate (MVR, measured to ISO 1133 at 220°C and 10 kg load) is more than 6 ml/10 min; the residual monomer content is not more than 2000 ppm, and the solvent content is not more than 1000 ppm. A: 40 to 100 wt% of at least one polymer A having an average molar mass Mw of 150 000 to 360 000 g/mol, selected from the group consisting of: standard polystyrene, impact-resistant polystyrene (HIPS), styrene-acrylonitrile copolymers, α-methylstyrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, styrene-phenylmaleimide copolymers, styrene-methyl methacrylate copolymers, styrene-acrylonitrile-maleic anhydride copolymers, styrene-acrylonitrile-phenylmaleimide copolymers, α-methylstyrene-acrylonitrile-methyl methacrylate copolymers, α-methylstyrene-acrylonitrile-tert-butyl methacrylate copolymers, and styrene-acrylonitrile-tert-butyl methacrylate copolymers, where, in the high-impact polystyrene comprising polystyrene and diene rubber, the diene rubber fraction is 5 to 12 wt% and the polystyrene fraction is 88 to 95 wt% and the sum thereof makes 100 wt%; B: 0 to 60 wt% of one or more further polymers B selected from: polycarbonates, polyamides, poly(meth)acrylates and polyesters and vinylaromatic-diene copolymers, C: 0 to 50 wt% of customary additives and auxiliaries, the fractions of A, B and C being based in each case on the overall molding composition and the sum thereof making 100 wt%, characterized in that the viscosity (measured to ISO 11443) of the molding composition at shear rates of 1 to 10 1/s and at temperatures of 250°C is not higher than 1×10 5 Pa*s and the melt volume rate (MVR, measured to ISO 1133 at 220°C and 10 kg load) is more than 6 ml/10 min; the residual monomer content is not more than 2000 ppm, and the solvent content is not more than 1000 ppm.