We were studying light in our science classes last week and learning about transparent, opaque, and translucent materials. We did the experiments, and then I had another idea, as I'm always looking for more hands-on projects. A person's head is opaque, and I've been searching for a reason to make silhouettes, so we did. 
To make a silhouette, tape a piece of paper to a wall. Have the subject sit fairly close to the wall on a chair. Place a lamp about head-height a few feet in front of subject. Adjust the position of the subject or the paper until the outline of the head shows clearly on the paper.
While the person remains as still as possible, have someone else trace the outline of the subject's head. (Blinking helps the eyelashes show up better.) Take the paper off the wall. Let the students carefully paint the outline using black paint and then fill it in.
Random fact: I haven't made these since I was in kindergarten in 1968, but I remembered making them, and I want my students to have the same opportunity. Students really do remember the hands-on stuff they do!