[G1911]

Originally Posted by oldeboo

I'm pretty sure no one here is that interested in discussing color theory, but anyhow, here are some ideas to think about.

I think it is very possible that there is a variation that you describe coming from the printing of these cards. True black is something that we haven't achieved yet, to my knowledge, here on Earth. Check out this link that discusses carbon nanotubes:
https://en.wikipedia.org/wiki/Carbon_nanotube

These color differences that we perceive on the backs of some of these cards, in my opinion, really are nothing more than variations of black in some cases. Yes, there is a clear difference visible, so for the sake of discussing cards they are different. Certainly information can be gathered about print runs and the different ink batches used. In my opinion, some of these variations of black are the same as the variations seen with Sovereign green and Piedmont blue cards. It's unsurprising that there are different formulations of black, just like with green and blue, or other colors. I know some will not agree that different variations of black exist. I'm just not convinced that every time we see something that doesn't look like a nice dark black it means that it was ink intended for something else. It's possible in some cases, sure, but it's also known that not all black looks the same.

Check out some of these different types of black, many appear blue, brown, purple, etc.:
https://simplicable.com/new/black-color

Again, yes they appear different to the eye and indeed are, so conclusions can be drawn about them in the card world. At the end of the day, I think this is why it is challenging to say if an Old Mill is "brown" or "black" when examining them on a computer screen. Differences in hand? Sure. Could the wrong ink have been used? Possibly. Could the ink have been mixed a little differently like with the Sovereign greens and Piedmont blues? Yep.

There are numerous ways to produce "black" ink. Was there clear intent to make Sovereigns different greens? Clear intent to make Piedmonts different blues?

I know color theory is not that interesting to most, but I'm not talking about different shades of Piedmont blue, but two completely different colors. Like Old Mill Blue, though I guess most of us only care for T206.

There may not have been intent to make different Piedmont blue's or sovereign greens, but there was surely intent to make them blue and green. Black and light purple are pretty far apart on the color spectrum, that's the difference I'm talking about, two very distinctly different colors in the box of crayons, and if it left the factory that way, not varying shades of the same color that every set and large print run will produce.