I meet (when I can) with a small ATC group once a month that usually has a fun little project we all can work on during the meeting. Last week Diana Hirsch supplied us with the official Zentangle "tiles" including a pen and demonstrated several patterns of Zentangle. I love that they are exactly ATC size. Apparently there are 109 official basic patterns, each with their own name. Seems to be more to it than just mere doodling ... who knew?