Brush pens offer a lot more variation in line width than the usual fineliner pen. Their nibs have a wide foundation that then tapers into a great place. Ordinarily the nib is made of a conical bit of felt, but there are actually pens which have a true brush tip https://paxtonbkpuy.weblogco.com/36863353/the-best-side-of-ink-pen-drawing-techniques