Alan...nope, most of the stuff you buy today is "tempered masonite".....doesn't swell and will retain any curve you put in it! It has a smooth side and a rough side....the rough side is where you apply the wet rags to facilitate the bending.
I've done several velour covered cab headliners that practically held themselves in place. The key is to make a good pattern out of an old headliner or one of the cheap repos.....it's a whole lot more economical than buying a fiberglass one-piece. I've used velcro sticky strips to hold it in place where decorative trim screws weren't wanted.
