You can use other speciality pens, like calligraphy pens, for line drawing. Most of these pens have specially developed nibs normally useful for hand lettering techniques. The Crow Quill helps make the thinnest lines I'm sure of beyond a Rapidograph. It's a scratchy feel and allows great precision. I use https://charlietmbpb.bloggactivo.com/35246074/how-to-draw-with-ink-pens-secrets