The beginning step of the painting process is to prime all the figures with a base coat of black spray paint that adheres to plastic. This ensures that the future paint job will have something to stick to, since acrylic paints will rub off of the plastic if applied directly.
The second step is to go over the minis with a coat of a light color using the zenithal shading technique. This term is derived from the word “zenith” which is when the sun is at its highest peak, and its light is beaming straight down from above. To achieve this effect, you airbrush a light color of paint, usually white, from straight above down to around 30 degrees. The lower and under hanging portions of a figure do not get any of the light paint color, and the result is a close approximation of natural sunlight and shade.
This step does wonders to a figure, as it helps the tiniest details appear like magic, which is a Godsend for people like me with less than excellent eyesight. This makes the painting process much easier since some of the near-invisible details are now easy to see.
I used white paint for the “good guys” and a green shade for the zombies. This will help to make it easier to spot your friends and foes on the table, until I get around to their final paint jobs (which might take a while!).