Dip pens are pens you dip in ink - they don't have any ink stored in them, and need to be dipped every few words or lines of drawing. So why would anyone still use these old things when we have pens that are so much easier? Well, there are a few reasons:
It's very quick to change ink colours - just dip in a different colour next time, maybe wiping on a bit of tissue if there was ink still on the nib.
Some specialist nibs are only available this way, especially where they're likely to wear out in use, or are easily damaged. If you want a really flexible nib, dip pens can be the best choice.
They can use inks that can't be used in fountain pens, including pigment inks and ink with shellac added for shine.
They're a nice old-fashioned thing that some people just enjoy the experience of using.
Along with a selection of traditional and unusual nibs from Brause and Manuscript, we have some of the most popular Japanese nibs from Nikko and Tachikawa - their 'G' nibs are very popular for manga and modern styles of calligraphy.