I just picked up a bottle of this over the weekend and thought I'd post a short review.
I loaded up a Stipula Etruria with a fine point and set out to see what this ink was all about.
After being a bit disappointed in the early going with the R&K Alt-Bordeaux, and later learning to love it, I'm holding out a final opinion of this ink pending more use. So far, I've found R&K inks to be reasonably well saturated, quick drying, and with low feathering characteristics on all sorts of paper.
Sea-Bluish does not disappoint! It is a true turquoise, sea-blue with little green. Instead, a clear, Caribbean blue color with darker edges around the lines it places down and good shading overall.
I'd say this ink is a bit bright for conservative use -- e.g. don't use it with clients or bosses which are easily put off, but for personal use, journals and notes, so far, it seems great.
In summary -- a true, ocean blue ink that behaves well on a variety of papers and has interesting shading!
Enjoy!
-- Jeff