My third book (Tufte's Second) is complete, I only have the first left to read, which I shall order once I have finished writing this post. Again there is plenty of excellent information in Envisioning Information, well worth the price tag.
Tufte offers many insights in the book, but two things initially spring to mind; the first is the use of colour within information design, primarily he examines and outlines examples which often call on nature for their palette:
He also delves into excellent examples of using colour for information, using colour as verb, noun or word:
The second thing that springs immediately to mind is discussed in a section on layering and separation, where Tufte introduces us to a foundational principal of information design: 1 + 1 = 3 or more. The simplest way to explain this concept is to see it in action:
While there are only two bars drawn a third bar is visible as the white space between the two bars is activated. This is generally something to avoid, or understood and used to ones advantage.
There are many more excellent examples throughout the book, and in all the other books for that matter; not surprisingly I'm looking forward to reading Tufte's very first book, my last, on the subject of information design: The Visual Display of Quantitative Information.... I'm off to order it now.