From illustrator Dave Devries book The Monster Engine which came about as an answer to the question: What would a child’s drawing look like if it were painted realistically?

Dave sez:

 It began at the Jersey Shore in 1998, where my niece Jessica often filled my sketchbook with doodles. While I stared at them, I wondered if color, texture and shading could be applied for a 3D effect. As a painter, I made cartoons look three dimensional every day for the likes of Marvel and DC comics, so why couldn’t I apply those same techniques to a kid’s drawing?

The Monster Engine: Children’s Drawings Painted Realistically (Amusing Planet)