A bit of a rarity, a dry highlighter does the same job as any other highlighter, but instead of it being in the form of a fibre-tipped pen, it's in the form of a pencil. A brightly-coloured 'lead' core will highlight your notes, letting the print show through, while a wooden outer can be sharpened and shaped like any other pencil. The perfect highlighter for anyone who prefers a pencil, or who tends to get lost in thought while going through their notes or reading, and forgets to put the cap back on!