I would be happy to share... most of my painting technique is picked up from tutorials or other people's models online. I 'discovered' this technique a few months ago while looking at Koyote's awesome somewhat-cartoonish models. The biggest problem I have with painting black is how flat it looks. If you look in some comic books, they will use a dark blue as a black so that it is not a mass of black pages. That was the same idea here.
I use four colors, and all of them from some craft store from years ago. Rather than using a sharp contrast in the highlights, the point here is blending, but in a lazy way. Water is an awesome aid. A normal black is used as a basecoat... more often than not its a flat black primer from a spraycan.
The second coat is called "Charcoal Grey." Probably any Dark Grey will do (75% black, 25% white or darker). From the paint pot, I will make a 1/3 water, 2/3 dark dark grey. This will be painted on all the raised surfaces so that the black serves as the color for the recessed areas. Blacklining is the intended effect. I make sure there is no grey where there shouldnt be. Note that this is not a dry brush unless it is for the finer details and I am feeling lazy. I usually skip this color for very fine details like the little chains or the place where the marine's mouth would be on his helmet. Basically anything that requires a 30/0 size brush to get to.
The third color used is a grey-blue. I forget the name off the top of my head, but this is a blue-grey. I will get back to you on the specific color. But this grey-blue is mixed 50-50 water/grey-blue at least. The high amount of water will make the paint somewhat translucent so the blending is easier without having to mix it with the dark grey. Also, instead of painting parallel to the edge, try to use the brush to apply the paint in perpendicular lines so that the highlight isnt obviously the same length away from the edge. All raised areas and edges get 2 or 3 fading highlights. Another way to say it is that you are trying to blend the dark grey into the grey blue so that it is easy to see the color change from a couple feet away.
"Hippo Grey" is the final color, about 50 to 75% white and 50 to 25% black. This is the only color that is used a highlight in the sense that it is painted only on the edges where light would reflect, and even then sparingly because it is in such sharp contrast to the other colors you would use. I do not water down this and use the flat edge of the brush so the highlight is very thin and subtle.
I hope this helps.
Edited by Lucumon, 12 October 2006 - 12:37 PM.