This is a brand new ink that Private Reserve has developed, so new in fact that the name wasn't even decided yet at the time I was notified I would be getting a sample. It wasn't until I received a sample bottle (not reflective of what the final, packaged product will look like) that I saw it is to be called Invincible Black.
Supposedly the word coming down from PR is that nothing they've tried yet has been able to compromise this ink. Apparently, the paper gives way before the ink does. Give me some ideas of fun ways I can torture this stuff, and let's see if that's true!
I'm also eager to compare this to Noodler's Bulletproof (which I should be getting in very soon) as well as the Pelikan Fount India ink I've been meaning to test for frickin' forever. I think a comparison review will be underway soon!
Private Reserve Invincible Black is brand new, but will be available very soon in 75ml bottles for $18 and 2ml samples for $1.25 at GouletPens.com.