I like me 4.2 vivace for lining but not as good as the kubin. I think my mc2 is a 4mm. I want a 2.5 vivace for shading and blending but I've always been told short strokes are not what you want for lining. Something about the inertial that's built from the longer cycle of the cam/armature gives a harder punch . I just know that throw my liner needles way out and need the long stroke so that the needle tips make it back into the tube tip when pulled up