Thanks, ernyoka. I already did it using the Maths mode. I don't want to hijack the thread, but I've been doing some experiments, and I thought I'd post the results. As I said before, I wasn't too impressed by the difference in quality between jpg and tiff for the displacement. Using a couple of maths nodes, I find I can use the original jpg texture for displacement and get even better results. I'd be interested in anyone's thoughts on this. First of all, here's a pizza with no displacement. mac