Here’s Tom Palmer on inking Neal Adams.
http://twomorrows.com/comicbookartist/articles/03palmer.html
”Other guys today try to pencil as if they were going to ink it, or they're trying to set it up for the inker. Neal penciled for penciling; the inking became another art that you brought to it. And I think that's what I was challenged by. He didn't put a line down that you just filled in. You didn't trace it—you had to bring something to it.
As far as inking over Neal, you realized you couldn't do it all in pen, nor could you do it just in brush—you needed both if you wanted to pick up what he was doing when he inked. He would probably render in pen, and then go back with a brush, and hit some of the heavier lines, and also some of the shadowing. You could tell, because it was a real juicy black line; it kind of forced me to match it.”