How to Make Sidewalk Chalk

When my girls were little, one day my oldest daughter got creative and started drawing on our sidewalk with some discarded chips from a plaster of paris project that I was working on. My plaster chips were tinted with powdered tempera paint, which were added while I was mixing up my project. I knew that my daughter was onto something the minute that I realized that plaster washed off my sidewalk as easily as the "real" sidewalk chalk did.

I started making my girls all of their sidewalk chalk. To make this, you will need a box of plaster of paris, some egg cartons, some powdered colors in tempera paint (or tubes of watercolor paint) and a big bowl-sized mixing container that you don't mind devoting to scratching and abuse from the plaster.

In your mixing container add some powdered plaster out of the box while being careful not to get the dust around your nose, eyes, or mouth. With a stick or old spoon, stir in little bits of water until you have a thick and creamy pudding consistency mixture of plaster and water.

Tint your pudding consistency plaster mix with a little tempera paint or soft watercolor paints that come in tubes; just a little bit of coloring goes a long way, so put your coloring in slowly, mixing after each addition, until you get the shade that you need. Scoop this tinted mixture into your egg carton holes and let harden for about 1-hour.

You can take the plaster out of the egg carton and use it instantly after about 1-hour, but plaster actually takes about 24-hours to finish hardening, so that the chalk will still be a little soft at the 1-hour point.

For some fun looking chalk, you can scoop three layers of plaster colors into each egg carton hole if you would like stripes. Or, when mixing, swirl in drops of color for a tie-dyed type of look. My daughter insisted that we try adding glitter one time, and that did not come out looking nice; the glitter seemed to get covered by the plaster so that it did not sparkle.

An interesting gift idea is to make your plaster chalk in candy molds that you no longer care about. Spray each mold with Pam or another type of non-stick spray before putting your plaster in. When you have a plaster pile of hearts, flowers, or decorative whatnots finished, they look nice in an old jar, or piece of florists plastic tied on top with a ribbon.