Think back to presentations you have attended in the past. I am sure you can recall some pretty boring ones, with traditional PowerPoint slides that obfuscate information, rather than communicate it. It might have been that the slides were made of a “ solid wall of text”  (a dozen or more full sentences written in a 16 font), which the presenter promptly read like he was reading a chapter from a book. It might have been the color contrasts that made the text illegible, spelling mistakes that made the text unreadable, or badly labeled graphs that were impossible to decipher.