Use a microplane, zester, or cheese grater to turn the chalk into powder.
In a large mixing bowl (I used one with a spout for easier pouring) whisk together the flour, water, chalk, and salt.
Add shaving cream and stir until well mixed and an even color.
Pour into squirt bottle.
Repeat with each color.
Video
Notes
For best results, use this paint right after you mix it up.This recipe is made with sidewalk chalk, which is washable. For easiest clean up, I recommend washing the same day.