Brush pens give a lot more variation in line width than a fineliner pen. Their nibs have a broad foundation that then tapers to your fine stage. Generally the nib is manufactured from a conical bit of felt, but there are pens which have a true brush idea manufactured https://ink-drawing-for-beginners92580.vblogetin.com/42672259/the-ultimate-guide-to-ink-pen-drawing-techniques