The 3D printing is an additive manufacturing (AM) technology, meaning that 3D printing machine produces a previously modulated 3D objects by adding and stacking different kinds of materials layer on layer. At the beginning the 3D technology was mainly used for prototyping but nowadays it is applicable in almost every branch of industry. Fused deposition modeling also known as thermoplastic extrusion will be used in the research; it is nowadays the most common 3D printing technique with respect to the price of materials and 3D printers as well as its fastness. FDM printers mostly use the thermoplastic filaments, usually Polylactic Acid or Polylactide (PLA) or Acrylonitrile Butadiene Styrene (ABS). They come in shape of wire coiled on the spool from which they are brought to the tiny heated extruding nozzle. Nozzle has a function of melting and deposition of the material on print-bed or alongside layer, depending on the data code. After one layer is built, the print-bed moves down by the distance equal to layer thickness and the building continues for another layer. The whole printing technique is getting faster, cheaper, wider, therefore better every day, the possibilities of 3D printing are almost limitless. The focus of the thesis is set on the mechanical properties of the PLA and ABS 3D printed samples, i.e. on the tensile strength of the 3D objects.