Pressure perpendicular to the skin. If the pressure on the textures very scene with friction will occur very. If pressure perpendicular to the surface at least, less friction will occur.
Force perpendicular to the contact surface. If a force perpendicular to the contact surface is very much friction. If the force is perpendicular to the contact surface is a little less friction.
Pressure perpendicular to the skin. If the pressure on the scene with a very touching surface friction. If the pressure is perpendicular to the surface, less friction.