This tutorial was done some time ago. Please keep in mind that just about everything I show here can be done several ways. It is pretty labour intensive so it's only for detail nuts. The instructions are specifically for Photoshop but the ideas apply to any paint application.
It was also made with Targetware in mind, presupposing 1024x1024 size files are used, specific numbers of pixels are mentioned. Please remember to adjust for any file size difference.
MAKING FABRIC COVERED WINGS
(This tutorial is for use with Photoshop CS)
This is by no means the definitive way to make fabric covered wing. These instructions are the methods I've arrived at after doing more than a few sets of wings for fabric aircraft. Most of this will be pretty easy to follow and the only "trick" method here is that I've distilled the operations to as few as possible while still maintaining the maximum amount of editability.
First, a note on directional lighting. The use of "painted on" shadows and highlights to simulate a specific light source might seem counter productive to use on a
3D object 
on which the light source will change due to the objects movement. Arguments can be made that painting a directional light source should never be done.
However, I see it is a necessary evil. Unless every curve and contour can be modeled as subtly as the real object, the detail must either be painted on in some way, or left off completely. I feel the detail is needed and also that it does look good on moving 3D objects. Also, I haven't found a way that can show the contours without using a directional light source that doesn't fall very short of the mark.
At least, if nothing else, you understand my reasons for why I paint wings as I do.
One other note, I use a left or top left light source but right will work also, just as long as it's consistent through out.
STEP 1 :
Start with the poly or UV map provided by the 3D modeler.
It helps if this is as accurate as possible. However, it may not be. The first step is to look it over very carefully to establish the wings edges and details. If the model is already animated, check that the moving surfaces are correct to the poly map. If not, you need to go on blind faith that the map accurately shows the surface locations. Any other details must be checked here as well.
This is the foundation you will use to lay out your ribs. If they don't line up with the 3D you may have to start from the beginning.
STEP 2 :
Lay a drawing of the wing on your PSD and line it up with the poly map.
This isn't vital but it sure helps to get the rib layout correct. It might be hard to get the ribs on the drawing to match the poly map perfectly, you'll just have to get it as close as possible.
Linear Mode
