If you are an animator or are studying animation, this book is invaluable. Wayne Gilbert has decades of animation experience behind his observations, and I couldn't recommend it more highly. For me, as an animator, it's a no-brainer to have this on my shelf with me at work. It covers far more than "just thumbnails," and does a great job of simplifying complex concepts such as force and you'll really get a great feel for what happens in the body when it's lifting something heavy or hanging or fighting. I can't tell you how many professional animators I know who swear by this book. It's short, but awesome.