I got inspired and decided to try out a few fountain pen inks the other day. I picked up Organics Studio's Nitrogen.
This is a popular saturated blue ink that has a lot of red sheen to it, looks almost like metallic foil when written on sufficiently ink-resistant paper.
I used it with a broad-nib TWSBI Eco. And in that, that, I agree. It does show a lot of sheen.
One really needs video to see the effect, since one needs to tilt it relative to a light source. A static image doesn't really convey the effect:
https://www.youtube.com/watch?v=NEsHNIn1c7w&t=1460s
But there were some big caveats.
It dries out very quickly on one's nib
My big surprise was how extremely quickly the ink dried on my nib, producing a delay until the ink is flowing and a hard start after just a short time out in the air without ink flowing. People do talk about this online, now that I've gone looking for it, but I wasn't aware of it when getting the ink, and I doubt I'd have gotten it if I'd known about this going into it. One can't just stop and think for very long without needing to start writing to keep the ink flowing. For me, this is frustrating, and really kills the appeal of the ink for me. None of my other inks do this.
One really needs ink-resistant paper to see sheen
Another thing that I hadn't anticipated
not having played around with inks with a lot of sheen prior to this
is that one really needs ink-resistant paper to see the sheen. On ordinary copy paper, it just looks like a blue ink. I knew that there would be a difference, but not that there would be no sheen. On an inexpensive composition notebook I've had sitting around for probably thirty years in my desk, it looks all right, if not quite as shiny as on Iroful paper.
This probably isn't a huge surprise to people who have used inks with sheen, and it's not going to be specific to this particular sheening ink. But I'd expected some sheen to still be visible on more absorbent paper, and it isn't.
It tends to smear and get on things
In the above video, Brian Goulet does mention this and how the ink is infamous for doing this
which I find puzzling, given how quickly it seems to dry out on the nib. So I was expecting to see this. But I still managed to get smearing and blue blotches on my hands multiple times, despite being careful. I haven't seen anything like this with the other inks I've used (though I don't have a huge collection, admittedly).
Other
It has a reputation for staining clear pens. I haven't tried cleaning it out after exhausting my current fill, so no first-hand experience with this, but I thought that I'd also mention this, in case someone runs across this post when considering the ink.
Summary
The ink is pretty, if one wants something with a lot of sheen. I don't dispute that. But it really is a pain in the neck to use.
I don't know of a good "Nitrogen alternative" that performs better, but I have to say that I wouldn't recommend it to anyone unless they are aware of what they are getting into.
One gallon is about 15.642197454545 pægl.