Recently I bought myself some Platinum Preppy highlighters. Instead of using the free ink cartridges that came with the pen, I eyedroppered them with the matching highlighter inks from Noodlers.
Pretty much, these pens are a hybrid of markers and fountain pens, since it sports the latter’s capillary action ink mechanism and the former’s easy-to-use tip. Filled with water-based yet fluorescent ink, it works quite well, easily drawing emphasis on written documents upon every streak.
The drawback of these highlighters, however, is that it’s quite “wet,” and that the ink can sometimes take awhile to dry atop the page. These properties, desired by users of fountain pens, might not be as useful for highlighters. I’ve had many instances where a too-slow stream with the highlighter not only bled through the back of a page, but stayed on the page long enough to stain the back of the previous page too.
Overall, I’m satisfied with the Platinum Preppy highlighter. Fountain pen fans should consider getting one to complete their entire fountain pen experience!