This one has been near the top of my Looking for Rationalizations to Buy list for a while. Unfortunately, there's no place I've seen that sells samples. Fortunately, I bought something from FPN classifieds and the seller kindly threw in a fistfull of samples, this one included. So, Einstein. He was known for having gray hair. And this is gray ink. I guess that's the connection. Or it could be *relatively* black. Either way, we come to gray ink. It's got a pretty good flow. About like any good ink. It's definitely gray, and not just watered down black, which I worried about. It has some water resistance, which is nice. Overall, there's nothing really really special about it. It's a good behaved gray ink that doesn't completely run away in the sight of water. It's nice to write with. I'd take some. But sadly, I can't really rationalize getting Einstein fan crazy over it, unlike De Atramentis Sherlock Holmes or Organics Studio Edgar Allan Poe. I wish they'd done something more special for Einstein.