Measured tensile strengths of outgassed and pure (1:0) dust samples formed from C6 and angular silica grains. The dust-to-ice mass ratios were varied between 5:1 and 1:1, leading to different VFFs after desiccation, and the measurements were performed after all water ice had been evaporated. Shown are fits to the data using Eq. (2) for the outgassed samples only (Fit A), as well as in the case of C6 for the samples that initially contained no water ice (1:0; Fit B). Additionally, fits with shared parameter b in Eq. (2) for outgassed samples made from both materials (Fit C) and for pure samples of the C6 dust (Fit D) are shown. Lastly, we applied a fit with the resulting parameter b from the previous fits to the pure angular dust (Fit D^*). The horizontal line shows the tensile strength of 1 Pa, a typical pressure achieved in the cometary subsurface by the evaporation of water ice at 1 au (Skorov & Blum 2012).