Legal graffiti. Create an image on a wall using water sprayed from a squirt gun or spray bottle. Document is disappearing. Fun!! The alley behind my work offered a variety of surfaces ripe for the spraying. After trial and error, I determined that the gray bricks were the best canvas – spray on the red bricks evaporated too quickly, spray on the rocks didn't show, spray on the trash cans just ran – and here is my disappearing star.