Add the flour into a mixing bowl.

Fold the shaving cream into the flour, mixing it as best you can (it will have some lumps in it).

Add the water in ⅓ cup increments, stirring between each increment, stopping when your mixture is a pancake batter-like consistency of thick and stiff, but creamy.

Next, add drops of food coloring and stir the color in until it is the desired colors and are consistent throughout the paint.

Add glitter and stir it in until the sparkle is consistent throughout.

Using a Ziploc bag with a corner cut off or a funnel, add the paint to the squirty bottle. I prefer to use the Ziploc bag because you can force the thick mixture down a lot more cleanly. You can also leave the paint in the mixing bowl and have the kids use a paint brush to paint.

Repeat the steps for each color that you are making. 

Proceed to play with your homemade outdoor chalk paint.