Primer huh?

I would prime with grey as OD is dark color and I use white mainly for bright colors such as red and yellow.

No, it is not your imagination…it is much stranger than that… (Just being silly!)

The ability of a paint to hide the color underneath it is called, oddly enough, "hide." It is a function of pigment load—the amount of particulate matter in the paint, and coating thickness. Darker color generally have better hide than light colors, but the degree of hide for a given color usually varies from brand to brand. Obviously, one solution to poor hide is to apply multiple coats and build up coating thickness.

I use a light to medium gray as a universal primer, except under colors that usually have very poor hide such as white (undercoat with silver), yellow (undercoat with white), and red (undercoat with silver, white, yellow, or a dark red, depending on effect desired.)

Triarius wrote:

No, it is not your imagination…it is much stranger than that… (Just being silly!) The ability of a paint to hide the color underneath it is called, oddly enough, "hide." It is a function of pigment load—the amount of particulate matter in the paint, and coating thickness. Darker color generally have better hide than light colors, but the degree of hide for a given color usually varies from brand to brand. Obviously, one solution to poor hide is to apply multiple coats and build up coating thickness. I use a light to medium gray as a universal primer, except under colors that usually have very poor hide such as white (undercoat with silver), yellow (undercoat with white), and red (undercoat with silver, white, yellow, or a dark red, depending on effect desired.)

 You coat use silver as an undercoat for white!?

i have never heard of that!  cool i will try it and thx for the help with the primer!

-Brian

Silver reflects more light, which enhance the white. You'll be pleased with the results!

I actually "prime" all my aircraft with silver, even the OD ones. I figure real aircraft are silver under their paint, so why not? 

You can use "hide" as an effect. Random sprays of white and black underneath a coat will give a slightly weathered, mottled look.