An important and interesting field of use of 3D printing is the production of parts exposed to physical stress. The strength of the component is influenced by many parameters. In addition to the material quality, fibre thickness, fibre direction, shape and size of the filling, possible composite fibre reinforcement, the conditions of use, e.g. UV light and air humidity also affect the component's load capacity. In our research, we examined 3D printed specimens. We examined the properties of four types of fibre fusion materials and five types of UV-hardening resins with tensile, bending, impact bending and twisting tests: PLA, PETG, ABS, ASA, Onyx, basic resin, water-washable resin, ECO resin, UV tough resin and ABS like resin test specimens made of materials were examined. The study also covered the effect of moisture content. We investigated the weight gain of the test specimens exposed to moisture as a function of time, and then the effect of the moisture content on the strength properties. After the tests, the surface of the specimens was examined with an electron microscope. The results can be well used to select the material and manufacturing technology of 3D printed parts exposed to physical stress and environmental effects.