Here is a scan of a Noodler's 1:1 prussian-blue + black mix, Noodler's black, Noodler's prussian-blue and Lamy blue-black. The paper is very absorbent, much more than my usual writing paper.

I've let the ink dry for 21 hours, then the right part was submerged in water for one hour. After the paper was dry again I took wet Q-Tips and did a smear-test with high pressure over the left 8 figures.

Conclusion:

Every tested ink is waterproof and doesn't change its color. The prussian blue and the Lamy got a little bit duller (Lamy blacker, PB lighter).

None of the Noodler's are smear-proof; the Lamy is. And this is exactly my observation in real-life use. I just cannot get the Noodler's to not smear on nearly any paper I use. Even if I dilute it 3:2 with water it still smears on my writing pads. At 1:2 (ink to water!) the smearing is gone, but so is the deep black and the lubrication.

For me it's an easy decision: As much as I would like to avoid iron-gall ink, I just cannot stand the smearing of the Noodler's inks. Maybe if my main usage were crossword puzzles in the newspaper, but on normal paper ...

By the way, the divider lines are sharpie blue and the text is written with a Pelikan F steel nib.

... and as a side-note: Mixing Lamy Blue-Black with Noodler's bulletproof is not a good idea , the mixture is not stable. A 2:1 mix showed coagulation.

Thanks for posting that, HankEr!

How does Noodler's Prussian Blue behave in your Pelikan or any other pen you've tried it in?

My Prussian didn't flow very well in a Lamy Safari F. It works perfectly in both a MB 145 XF and a CS Drake IF.

I've only tested it in the Pelikan M150. Flow is good but it feels (lubrication?) a bit drier than Pelikan 4001 Black or Lamy Blue-Black.