I was recently on a quest to find the perfect blue ink for my fountain pen. I wanted a bright royal blue. A few that I tried had the right hue but were too transparent. There seems to be a balancing act between pigments and color depth for inks, and also not clogging the pen. I do have a purple ink that I like very much, but it just won’t do for legal and more official paperwork. Also a lot of inks look fine when you first write, but dry and fade over time into something less appealing. It’s like when I pick up pebbles at the beach. Most of them look gorgeous when they are wet, but once they are home and dry, I am disappointed. Anyway, I’ve settled for now on Omas Blue, which is on the higher end of the price scale for inks, but definitely affordable (their Vespucci Red is supposed to be amazing). I discovered that someone actually has actually created a book of 200 hand painted ink samples. You can buy it for $27.50.