As part of being an artist at the Pasadena Chalk Festival, you're highly encouraged to donate a canvas for the festival to raise money for the Lightbringer Project, a group that helps bring art to underserved kids in the community.
The first year you participate in the Chalk Festival it's $30. Every year after that it's free! When you're there, they give you plenty of chalk, water, snacks during the day, breakfast, tote bags, shirts, and artist dinner on Thursday, and there's awards for the winners. They even give you a blank canvas to return with paint on it! Painting a canvas seems like a simple thing to do in return.