Over the past few years were developed some manufacturing processes involving resin impregnation in dry preforms prior to cure, and more specically resin infusion across the fabric thickness in the so-called Resin Infusion Processes. Therefore, in these growingly used processes the transverse permeability of the fabrics will control both manufacturing cycles and dimensions, and consequently the mechanical properties of the nal composites. A big eort has been realized to obtain reliable experimental techniques for measuring the transverse permeability. Since the dierentiation between saturated and eective permeabilities is still discussed, and the flow front is hardly dened in such small dimensions (order of 1 mm), our measurements on some so-called Non-Crimped New Concept (NC2) are carried out for saturated flow, i.e. the ber network is completely impregnated from the onset of the experiment. In our case [1], these measures rely on the measurements of the pressure drop induced by the flow of a controlled liqui across the fabrics, easily converted into transverse permeability through the Darcy's law. One of the main results of these measurements is that the low NC2 transverse permeability depends on the face of the fabric receiving the liquid. This original behaviour may, in turn, be translated into manufacturing guidelines to achieve optimal processing conguration. An attempt to relate this dierential to the stitching hole surface is proposed which turns to explain minor phenomena. On the contrary, the 3D shape of the stitching hole reconstruction from polishings could yield some proper explanations.