In composite manufacturing processes, such as automated placement technologies, it is essential to master the tackiness of thermoset prepregs. Obviously, the resin is responsible of this character, however the present experimental work aims at highlighting the influence of the textile reinforcement. A rheometer is used to carry out a probe-tack test on several industrial carbon/epoxy prepregs. The results are interpreted in a phenomenological point of view, and the relationship between the failure modes and the shape of the stressdisplacement curve is established. Thus, it is shown that textile reinforcement plays a crucial role in tack properties, by means of its organization (fabric or UD), thickness, or the roughness it induces.