Drawing is a universal tool of communication to create or to invent pictures, to illustrate a poem, to prepare a project, to provide explanations. The artists are not the only people to draw. Engineers, architects, scientists, teachers and many other people draw for their researches, for teaching or to demonstrate. This crossdisciplinary dimension shows the timeless and universal nature of drawing, From the nervous sketch to the finished drawing, from the heritage dimension to the contemporary creation, the choice to use drawing techniques, is used by people in numerous fields to explain their work and practices. There is no difference between looking for beauty and precise representation, between aesthetics and didactics, between art and sciences. Exhibition: ULB de l'Université Libre de Bruxelles, Brussels, Belgium (2011-2012).