with A 0 = w 0 t 0 being the cross-sectional area, width, and thickness of the pristine unstretched sample, respectively. Another test to investigate fracture properties of (soft) materials is the trouser tearing test (Figure ). A rectangular sample specimen of width w is cut along its length to give two identical legs, which are clamped and pulled in opposite direction with a force F. At a certain critical displacement length the crack will start to propagate and the subsequent tearing process can be catergorized into steady and stick-slip tearing (Figure ). For steadystate tearing, fluctuations of the tearing force remain low and the tearing behaviour is best represented by the average tearing force F ave . For the stick-slip tearing mode, distinct fluctuations of the tearing force occur, the latter regularly reaching a maximum followed by a sudden and rapid decline to a local minimum. In this case, the tearing energy is often derived from the maximum tearing force F max . In both cases, the tearing energy T (kJ/m 2 ), which is synonymous with the fracture energy Γ, can be calculated through equation 8: