This Canvas String Art Graffiti project is fun for kids and adults alike. While this is a spray paint project, you can use alternative paints or dyes for younger children. Makes a fun summer art project when your kids get bored.
Lay down big puzzle pieces and spray paint over them. Wait until they dry to take the off. These would make beautiful autism awareness shirts. Autism Speaks is bad news bears for actual autistic people! Cool shirt though.