Stress softening during the Mullins experiment (hysteresis tensile test) is a phenomenon of filled and crystalline rubber respectively. Previous publications presented different theories to explain the effect at the molecular level. These theories include for example bond rupture, molecule slipping, filler rupture and disentanglements. But the mechanism of the Mullins effect is not solved finally. Moreover the literature reports mostly one material with a model fit. Publications which compare different materials are missing. The question remains how to compare results of different materials. Liquid silicone rubber (LSR) is a material with a broad range of mechanical properties. These greatly depend on the amount of filler, the degree of curing and the type of curing agent. The hysteresis stress-elongation curve is different for each type of LSR caused by these factors. The aim is to find a characteristic value which allows to compare different rubbers. One possible value is the loss of force at the maximum elongation ΔF and another the elastic recovery Δε. It is also possible to compare the area which is a value for the irreversible damage. Another possibility is to observe the decrease of force at one defined elongation (e.g. 50%).