You can utilize other speciality pens, like calligraphy pens, for line drawing. These kinds of pens have specifically built nibs generally used for hand lettering techniques. The Crow Quill would make the thinnest traces I do know of beyond a Rapidograph. It has a scratchy sense and lets good accuracy. https://how-to-draw-with-ink-pens47147.thezenweb.com/facts-about-ink-pen-drawing-techniques-revealed-74196877