Very similar to Robert Oster Purple Soul
Robert Oster Signature Inks are always well made, well-behaved and have excellent shading. This ink arrived today, and has been put to task, going through my rigorous testing on multiple papers in pens ranging from Jinhao, Lamy, Twsbi and a very picky Monteverde. This particular ink is not a traditional blue-black, but closer to a purple-black. Think of something like Diamine Eclipse or Oster's own Purple Soul. For a blue-black that is closer to blue, go for Oster's Midnight Sapphire, another lovely ink. This Robert Oster Blue-Black is still a gorgeous ink. It has great depth, especially in a wetter pen, and it has some lovely red sheen around the edge of pooling. Dry time is fair, and on the papers and pens I used it in, there was not bleed or feathering. It is however, not overly water-resistant, so keep that in mind if that is important to you.