As anyone who has suffered "death by PowerPoint" knows, graphics can provide the key insight or, most often, lead to utter confusion. This book tries to move technical illustrators toward the former.
I really enjoyed the earlier parts of the book, which I think offer practical advice and examples of making technical graphics work. It can be as simple as using color sparingly, or eliminating it entirely. Or aligning key elements in just the right way. Just looking through the examples can spur thoughts about how to make figures more clear.
Some of the case studies, unfortunately, impressed me less. They often involve very intricate structures, with graphical solutions that evolved over months. Most of these will not be helpful to average (i.e., well above average) person trying to clearly explain a complex technical point. It's not that they aren't impressive. But you don't learn to paint by having someone put a Raphael in front of you.
This book is worth the investment for the early chapters. Don't worry if some of the case studies leave you lost.
I was provided a copy for review by the publisher.