Making your own sidewalk chalk is a fun and easy project that kids will love. Learn how to make heart sidewalk chalk for Valentine's Day! It's a fun project for kids (or a cute Valentine's gift)!
Mix together the water and plaster until well combined.
To make colored chalk, add tempera or acrylic paints (or food coloring). Add a small amount of paint and then fully mix it to completely incorporate the coloring. Add more, as needed, until you are happy with the intensity of the color.
Pour the mixture into silicone molds. I used a silicone heart-shaped muffin tin for making heart-shaped chalk which is great for little hands. To make long, thin chalk, we used silicone molds meant for making ice cubes for bottles. They both worked really well as chalk molds.
Allow the plaster to dry.
Unmold and have fun writing on the sidewalk outside.
Video
Notes
Plaster of Paris works better than harder plasters for making chalk. They will write better on more of a variety of surfaces.Using paints will provide a much brighter color than food coloring.For larger sidewalk chalk similar to that sold in stores, you can also pour the plaster mixture into cardboard tubes (like the ones leftover from finished toilet paper rolls) instead of silicone molds. You'll need to cover one end to hold the mixture inside.In most cases, you should be able to unmold the chalk after several hours. When using a lighter plaster and/or delicate molds, though, it may take a couple of days to harden and dry out enough to be able to unmold it easily without breaking.