Editing to Help Students' Backs 
Perhaps the worst way to condense a book is by using smaller or condensed type; you want to be especially careful that all fonts are legible. Neither should you save space by tossing out pictures or diagrams that clarify subjects. Some engineers cram paragraphs together, but paragraphs are valuable structural devices that can make subjects more clear. So the clue to successful condensation of text is not mechanical miniaturization but literary efficiency.
Bush, Donald W. Intercom (2003). Articles>Education>Writing>Minimalism