Each sample was printed both with horizontal and vertical layer orientation and each one had a twin copy that was used for comparison at the end of the test. The settings of the printer (Delta Was 20x40) were: nozzle size 0,7 cm; layer height 0,4 cm; wall thickness 0,8 cm; top/bottom thickness 0,8 cm; infill 5 %; brim 3mm. (2) Polypropylene samples were printed trough a 3MT with 2mm nozzle size, due to difficulties in printing with the smaller printer. The samples are already laterally deformed before the test. Printing temperatures (extruder and bed) were varying according to material properties. The materials employed were (see Fig.4):