There's also the fact that even the best-sealing fountain pens (and most seal poorly) only deal with those water-based inks, so with significantly more volatile inks I'd worry about leakage (a ...

First up? Diamine Regency Blue. This puppy is DAAAARK. Goes down almost black, and is a deep, deep indigo blue-black when dry. It definitely stands out compared to the LAMY Blue, but it's difference ...