We play with sidewalk chalk all the time, its one of my kids favorite summer activities! We usually just buy chalk from the store but did you know you can make it too?
Here is a simple video tutorial that walks you through the process of making homemade chalk.
You can also make your own liquid or spray chalk by simply mixing 1 Cup of cold water with 1 Cup of cornstarch and adding a tiny bit of food coloring. You can then pour it into a spray bottle and let your kids spray away or let them paint the driveway with a paint or foam brush.