3D-printing covers a wide range of different technologies whose usefulness has proven in many areas. The final task deals with a fused deposition modelling (FDM) technology. Presented is the process of producing specimens of polyamide 6 for Charpy impact and three-point flexural test, where the parameters of the infill structure and the percentage of the infill is changing. We discovered that the impact strength of the test specimens falls with rising percentages of infill, while the flexural strength increases. The maximum force and flexural strength are achieved in specimens with a 100 % infill, while the maximum impact strength is achieved by the specimens with a 0 % infill.