Layering and Separation.
First, I am still confused what he meant by "1+1=3 or more" in the article. He introduces the technique of layering and separation for information design. I thought it was interesting that he saw bold boarder lines as "cluttered", and not very visually interesting. When he said layering and separating the data, I couldn't fully understand how he actually used it to make look better. For me, when I think of layering something, I imagine the set of "Layers" in Photoshop program. In this article, he says he used layering and separating by making bold boarderlines of the boxes lighter (Symbol Sourcebook). I understand that the thinner outlines work in more designerly way, or I will say, aestheic and elegant way. However, I still see the use of thick boardline is also necessary in some occasions, and they'are not really bad design for me. They just have different feel to it.