One of my favorite colors is Diamine Blue Black. A bold and dominant ink with wonderful shading and great drying behavior.
Here are two minor issues that haunt the ink:
1. it is much runnier/thinner than other Diamine inks. In my wet Omas pens this ink lays down an EXTRA WET line, a bit wetter than I usually like.
2. the ink, when used in a pen, will produce a slight caking of crystallized dye alongside the nib slit on top of the nib and often also underneath in the course of time (usually it takes a few days for it to build up).
Has any of you had a similar experience with this ink? Point 1 can be beneficial if you use a stingy pen to optimize the ink flow but for wet writers to start with it is not necessarily the best ink. Point 2 is not necessarily pretty but you can wipe the slight caking off without any residue/staining.