Brush pens offer far more variation in line width than a fineliner pen. Their nibs have a broad foundation that then tapers to the fine place. Normally the nib is manufactured from a conical bit of felt, but you can find pens that have a real brush suggestion manufactured https://lanewekos.free-blogz.com/84052641/the-smart-trick-of-how-to-draw-with-ink-pens-that-nobody-is-discussing