(Jeff Abbott is a regular contributor at The Pen Addict. You can find more from Jeff online at Draft Evolution and Twitter.)
Blue inks are a weakness of mine. I'm always searching for something that's a little different and interesting compared to the ones I've already tried.
JetPens recently started carrying small trial size bottles of many Diamine inks, and I've been trying those out pretty frequently.
Asa Blue is one of those inks, and it's probably one you've heard of before. This is one of those standard blues that gets recommended quite a bit. Even though I've known about it since I first started using fountain pens, I'm only now just getting around to trying it.
In this case, better late than never.
Color
Asa Blue is a deep, rich blue. I'd call it a royal blue, and it lives up to the name much better than Kaweco's version of the color. Calling it navy might be too much, since navy is closer to blue-black in most cases. Either way, this is a standard blue that looks fantastic and fits in professional environments with no problem. This ink won't turn heads because of its stand-out color, but it might for the small amount of shading it exhibits.
I think the best way to describe this color is to compare it to most blue gel ink pens that you can buy. It's a standard blue, and it looks fantastic. And, like I said earlier, this is a deep, dark blue, but I wouldn't classify it as a blue-black.