"Actually (!!) if you look at the original story -- especially in the black and white ESSENTIALS -- you will see that it was always my intent that Logan have a white streak on the top, too. It was just colored (or more likely separated) incorrectly. "

This is something I've always meant to ask; what is color separation, actually? What's the process? And how can it go wrong?

Great stuff! Looking forward to the rest.

And that's without even counting times plates got dropped (left out) or flopped (blue plate run as yellow, for instance).

At some point, for instance. Darkseid's arms and legs turned pink. Originally they were gray, like this face. When I came to do FOURTH WORLD, I had to fight to have them restored to their proper, original colors. The mistake had become canon. (Sort of in the same way characters with a lot of black in their costumes so often end up with a lot of blue in their costumes.)

"...take the guides and copies of the art, and laying a sheet of vellum over the latter, black in all the areas that were to be whatever percentage was required of each color. Say, blue (cyan). So you'd end up with, usually, three sheets of vellum which would then be used to produce the blue plate."

My head hurts trying to visualize all this... so in other words, these sheets of vellum had no actual color on them, they just were arbitrarily designated as the "blue sheets", with the blue areas of a given piece of artwork marked in black? And they needed multiple sheets of vellum because each sheet would be designated as a different percentage of blue?

Now, forgive me, because again, I'm having trouble visualizing this... if vellum, as I understand it, is a kind of parchment, how would laying it on top of the xeroxed artwork aid them in designating which areas were which color? Were they transparent, like tracing paper? And were they then imprinted on actual metal plates which were used to stamp the color on the printed pages?  I have the feeling that I'm completely misunderstanding this.

But I gather the major stumbling block in all this, which was eventually solved by computers, was that they couldn't create a system of codes to represent every possible color combination, and send that info directly to the printer, because that would be too hard for a human being to keep track of.

Regarding the blue/black thing in character's costumes... Venom comes to mind, but is it also true that Spider-Man's costume was originally meant to be red and black, but it was simply too hard to consistently achieve in a way that looked good with the technology of the time?