Tessellations & M.C. Echer
Found this site (tessellations.org) recommended in this thread on AskMeFi. It's on tessellations and how to make them. Tessellations are those drawings that M.C. Echer did, the ones with the repeating patterns.Here is a blurb from the site recommending a book on it.
"...One book I would recommend above all others was written by a quilt designer and not a mathematician. She began at the beginning and investigated it all from scratch. As such, it is easy to understand and full of diagrams and lavish illustrations - 'Designing Tessellations' by Jinny Beyer (ISBN 0-8092-2866-1)"
I've ordered it at the library but I think I may try it this weekend from the instructions on the website.