Wall art on the fly, part one

The night before the California Gift Show started, I found out that I had a 20 foot wall to decorate for my make-and-take craft area. My only resource at that late hour was a local office supply store. I bought some foam poster boards, markers and drew four images. At first I planned to color them, but then decided to leave them pretty much blank so the convention guests could do the job. Here is the 'before' picture!