The limit condition for the flow rate at the wall for a Newtonian fluid with various solid/liquid interfaces was studied experimentally using an original high resolution technique. A notable interfacial slipping was shown for the hexadecane flowing on a surface with low roughness and covered with methyl groups (non wetting surface for the hexadecane). The systematic study of various modified surfaces made it possible to identify two key parameters fixing the amplitude of slipping at the wall and acting in an antagonistic way on the roughness of the surface (geometric and chemical) and the fluid/surface interactions.