Dear Prof. Ramsay, Many thanks for your reply! This sounds like something I could use. I enjoy using the earlier 2 volumes of this series. Now that I've been to Angelsey (in early 2000), examples shown in the folding and fracturing volume have much more relevance. I started to work through Turcotte & Schubert to understand something about continuum mechanics, but plan to switch to the 3rd volume in your series. Superposing folds is such a lot of fun! I got the students to do it with me in the class, using paper and mouse pads. I think they enjoyed it. Regards Stephen White