Some more ink comparisons. First, a couple more diamine inks:

Diamine Midnight	Cult Pens Deep Dark Blue

 

I did this because when I tried a freebie cartridge of Midnight my first impression was it’s exactly the same ink as the Cult Pens Blue — but side by side the latter is darker. Still, the hue is similar:

Both blues appear to be a fairly “true blue” with no green or red leanings, though from the chromatograms (Deep Dark Blue on the bottom) they have a grey undertone. I don’t know if the separation with the bottom ink is better because of the ink or because I put too much on the top sample.

Next, some turquoise:

Lamy Turquoise	Waterman South Seas Blue

 

Mostly I like turquoise for annotation with a very fine nib, and the lamy turquoise is a bit too light for writing with a fat nib. I’d choose the SSB for all-round use although Waterman changed the name to Inspired Blue and I’m not 100% the inks are exactly the same. Some say it’s just marketing, others suggest there may be a difference. I got a genuine NOS bottle of SSB because it was cheap and I like the old label better than the new with its French name (Encre Bleu des Mers du Sud).

So, two sets of two inks, very similar. Just like the greys and the reds most people are unlikely to care about the differences. I’ve also heard people say that of all the colours turquoise is the most similar between brands. It’s just… turquoise. You either want a nice vibrant blue or you don’t. But whatever you choose I’m pleased to say these are all nice safe inks, flowing and lubricating well with easy clean up. The Diamine colours are very wet, Lamy is a little dry and Waterman is “just right”.