Most researchers have investigated in soil fabric from the particle point of view, while very few have successfully examined void fabric in 3D in detail. The current study builds on the work of Shire et al. (2012) who looked at the orientations of constrictions in materials subject to an anisotropic stress state. Here, the analysis is focused on the void topology – elongation, volume and orientation – via two alternative methods: the tessellation of both voids and particles in tetrahedra following Reboul’s algorithm (2008) and the study of voxelised images using watershed segmentation.