I'm definitely going to buy a bottle of this, and soon. I tested it in a TWSBI Eco with a broad nib, mostly on Black n' Red Optik paper and a little on Claifountaine paper. I'm still new to fountain pens, but I liked it very much. It's by far the wettest ink I've tried so far -- for reference, the others were J. Herbin Perle Noir, Poussiere de Lune, and Violette Pensee, along with De Atramentis Document Violet. With the broad nib, the ink is much darker than I expected, even though I saw many reviewers say the same thing. It looks black in most light, especially when next to a lighter ink. But even next to black, it looks almost black, but not quite, and there is a vibrancy and intensity to the color and degree of saturation that black ink doesn't have. If you look at it closely, though, you can see that parts of it look purple. It has lots of shading, considering how dark it is. This strikes me as a perfect gothic-looking ink. However, it's also dark enough and subtle enough that I think it would work well in professional settings, though admittedly I'm not in office work, and so not an adequate judge of that. It's an extremely wet and smooth writer, and very well-behaved, with the sole exception that it is *very* hard to clean out of pens. So you may want to dedicate one pen exclusively to it, which is what I plan to do, and be careful with it with your demonstrators if that bothers you. I haven't actually tested it in on cheap paper, but I strongly suspect that with how wet it writes that it would bleed through that, at least a bit. But it didn't with good paper. Another caveat for people with allergies, asthma, or sensitive noses or lungs is that it has a pretty awful chemical smell, which is seeming to me like it might be common with purple inks, as three of the four I tried did, but it's really only a problem when refilling the pen. This is probably one of only three inks I'll keep a pen inked with at all times -- the others being Poussiere de Lune, and a waterproof or water-reistant black ink when I find one I like enough to buy a bottle of. I did not personally test the water resistance of this ink, but I'm ranking it highly because I've seen it reviewed as good here and elsewhere online. Images are a test page written on Black n' Red Optik paper written with a TWSBI Eco with a broad nib with the flash on and off.