Samples depicted in Fig. had electrically conductive CB-PLA pathways, with dimensions N×2×50 mm 3 , where N = 1, 3 or 5 mm, to measure changes in the electric properties during the tensile resistance tests. These samples were labelled as 3DP_N. For this purpose, electrodes with printed contacts (as seen in Fig. ) are attached to a source-measure unit (2450, Keithley). The distance between the electrodes was 70 mm. Resistance was measured in a two-wire configuration, with the constant current value set at 100 μA for all samples. Then, resistivity (ρ) was calculated according to eq.