Blind Line Drawings

My 4th graders worked on 2 pencil portraits of their partners in their sketchbooks this week: one where they were allowed to look at their paper, and the other where they could ONLY look at their partner and were not allowed to look at the page until they were done.  The partners had to "pose" and the sketcher could either do a shoulders-up portrait or a full body, (some chose to do one of each).  For both portraits they were NOT allowed to pick their pencil up off the page, even to get to the eyes/nose/mouth.  I heard a lot of grumbles about "HOW?!?" and heard over and over that they didn't want to "ruin" their pictures by having lines in them.  I told them to trust me, and when they saw the finished products, they begged to do the project again.  It's now one of their favorite "early finishers" activities!  They chose their favorite of the 2 (or 3 or 4,) drawings to trace with a black oil pastel and paint in with bright water colors.