This communication sought to redress the loss of the skill of making marks while reading by reporting a consolidated and reflective summation that drew on over four decades' worth of experience with approximately 500 undergraduate and 200 graduate students of Production Engineering at the Federal University of Rio de Janeiro. It identified the fundamentals and rationale of making marginalia while reading, with particular attention to their role in the preservation of insights and in furthering discovery, pointing to the need to (...) develop emotional as well as intellectual signifiers to allow readers to capture and recall their understanding of the texts they read and the significance of their marks. This supported the framing of relevant issues in the passage from reading and marking on paper to digital books, pointing towards approaches that would allow better understanding of the shortcomings of this medium for making marks while reading. (shrink)