I see what you mean, Alexander. At first I thought of using slides, but I hear there are only a few expensive ways of getting them printed in the traditional manner (that is, other than scanning them). I think that whoever asked for prints was thinking of avoiding digital files for one reason or another that I can't guess either. Maybe they just don't want to look at the images on a computer screen.
I guess you have answered my question, anyway. If there's no color film that will do the job as slides would, then I'll shoot slides, scan them and have them printed. Then I'll have to wait and see the level of accuracy of the prints.
Thanks for your tips too, Venchka. I had already decided I should use a tripod, but using a polarizer hadn't ocurred to me.