The above illustration shows the combined use of the original line art and a gradient overlay of the finished cutaway car illustration. Because the whole of the line art is on one layer, the mechanics on another layer and the body on the top layer in Photoshop, this allows for different emphasis to be given to whatever parts the client wants to show.
The above series of illustrations show the line art in full, various color ways of the same illustration, and the car body as illustrated without ghosting. Although it takes a longer time to paint everything fully, you eventually have multiple layers in Photoshop that you can adjust in various ways.
