Sidewalk chalk is pretty darn easy to make, and by doing it at home, you can save money, create your own designs and colors, and have fun with the whole family.
Step 1: Materials
You can get everything you need for this project from a craft or art supply store and around the house. You'll need:
Plaster of Paris
Powdered Tempera Paint
I used some fun molds that came with a plaster of Paris kit, and some of the neat ice tube trays from IKEA. They even make tube-shaped ones if you want traditional chalk shapes.
To make your own stick molds, try using toilet paper rolls. To make them thinner, just cut a seam, overlap the edges, and tape together.
Step 2: Mix it up
For every cup of plaster of Paris, use 3/4 cup of water. Add in as much powdered tempera as you like, and stir, stir, stir!
I found that the color of the chalk when using it on paper didn't come out as strong as it seemed like it would. So be prepared to do some experimenting.
Step 3: Molds
Pour the mixture into your molds. For fun, mix up a few different colors, and swirl them together!
I used a wooden skewer to level off the tops of the molds so they'd have flat backs.
Step 4: Clean-up!
Clean up is very important - and you don't want to rinse this stuff down your sink. See how it's setting up in those molds? It's going to do the same in your pipes!
Take a container like a small waste bin, and line it with a plastic bag. Pour in some water, and use this as a sink to rinse everything - all materials, your hands, everything! Let the plaster set up in the bottom, and the water will rise to the top. Once it's settled, you can pour off the water from the top, leaving the plaster undisturbed. Dispose of the bag.
Step 5: Check out that Chalk!
Drying time will vary, depending on size of the molds you use. It's pretty easy to tell by look and feel when the chalk will be ready to de-mold. Even if you pop it out and it's not set yet, you can let it air dry a bit more without worrying about it losing its shape.
Now get outside and make some art!!