The first step, is to save in the proper format. For Forgotten Battles, that's 8-bit indexed color.
You can do this in your paint program but don't do this to your template! Keep the template at true color (also called 24-bit mode) Start by saving a .bmp copy from your template. I use Photoshop Elements' "Save as..." command so that my layered template is safe. Then close the layered template, and open the newly saved .bmp file of your skin, you'll prepare this for game use.
To begin with, you can save straight to 8-bit color right in the paint program. The results are decent, but not excellent. Once you understand the process, you can use BRIGHT for a very optimized conversion to 8-bit, with results that have much less banding.
To get this finalized skin into the game, you need to find the main FB install folder, and inside there is a skins folder. For each plane in the game, there is a skins folder here. Just place your new skin into the folder corresponding to the plane it fits, being sure not to overwrite the original void or any default or skins you added previously.
In the game, you'll load up FB/PF and start a mission. On the arming screen, you can pick your skins for each plane.
That's a short answer, if you are stuck at any part, just post back and we'll get some more help.![]()