I find that diagrams and illustrations for science are so often NOT GOOD, NOT EXPLANATORY, and are TOTALLY CONFUSING.  Here is an example. It is from a very nice article, (Biochimica et Biophysica Acta 1793 (2009) 5–19), but the diagrams of the arrangement of cristae just doesn’t make visual sense.  It is an injustice to readers to create confusing images and put them up as learning aids.  THis diagram misuses the shading when it creates a look of 3dimsnsions…. it makes no visual sense in any of the three drawings in this figure.  To create shading on one portion of a diagram (e.g. the middle figure) which in this case was the intercristae space, which is called the intermembrane space, and NOT make the shading equivalent on the mitochondrial matrix is just careless, and misleading. The lower diagram is beyond deciphering…. it looks like there are three orange fingers poking up, from a space with holes.  Nothing resembling anything that is shown with real TEM images.  So sad.  It wastes time and  sends wrong information.