So I've just learned about "spotting blacks." It sounds troubling, but it's actually a really useful tool for comic book artists. And it made me realize why I love the Hernandez brothers, Milt Caniff and Jack Kirby so much. They all do this with the greatest of ease.
Okay, so here's a random panel taken from The Black Coat (which you should check out!):
This is Francesco Francavilla inked by Jeremy Colwell if I'm not mistaken. If you look at the ominous shadows on The Black Coat, there is more than a shadow, but a sense of weight to his body. Especially the head and legs. The same with the anchor on the left.
Now the sun, or negative space in the center is such a contrast that our eyes almost follow around it. If you look at a page layout, you can usually see big chunks of black that pop out at you. Our eyes are so used to looking at black letters on white pages that we are trained to see dark areas as objects and light areas as negative (or unimportant) space.
Using this techniqe allows readers a movement from panel to panel that ties each one together. If you look through any of the "phonebook" reprints from the 60s (a perfect example is Thor's costume; black vest, white circles and brush strokes throughout the cape), you'll see this pattern emerge.
Comic artists still use this method, but not nearly as skillfully as someone like Jack Kirby. They are of the mindset that coloring will add that extra dimension. But it is just as important to push the black areas in color comics as with black and white. Not to diminish the importance of coloring, but the main body and weight is in the black areas. Have you ever seen a movie where the black is sort of grayish or washed out? That's exactly what happens with comic pages without healthy doses of black. They feel two dimensional, no matter how much shading or gradients are applied.
A lot of artists end up doing this without thinking about it, simply because it's so prevalent. But it's good to take a step back and try it out.
Here's some panels I'm working on without speech or borders. I'm no Jack Kirby (or Francesco Francavilla), but I think I'm pretty good at matching the black areas to draw out the important elements.
There's a huge article with lots of examples in Draw magazine number 14 of Summer 2007
Here's a ton of pages where you can see the rhythm of using black as a weighty shadow.
And I couldn't really find a good explanation of it, but there's another blog where this guy tries to explain it as well:
Stephan DeStefano's blog;