So I decided to make sidewalk chalk party favors when I found these ice cube trays at Ikea. Fish and starfish shapes! Couldn't have planned that more perfectly if I had tried.
Only problem was, all the recipes I found for sidewalk chalk called for powdered tempera paint, and I could only find it in great big jars that cost around $10 for each color! Then I discovered this recipe, which claimed you could use powdered OR liquid tempera paint. I decided to give it a try. It was quick and relatively easy, and the chalk turned out great. Just a few minor bumps along the road.
Below is my modified recipe and notes on the process...
For each color you'll need:
1/2 cup warm water
3-4 tablespoons washable liquid tempera paint
1 cup Plaster of Paris
Large plastic mixing container
Silicone ice cube mold
1. Pour the warm water into your mixing container, then sprinkle the plaster powder into the water a little bit at a time until it no longer dissolves (about 1 cup). Stir thoroughly. (Be careful not to mix in too much of the plaster powder or it will set before you can pour it into the molds. It should be about the consistency of pudding. It still works if it's a little thinner, just takes longer to dry.)
2. Add tempera paint to the plaster mixture and stir until blended. (I just added paint until I liked the color. Didn't seem to hurt the finished product at all.)
3. Pour the colored plaster into the molds and gently tap the mold on a flat surface to bring up air bubbles. Let dry for 3-4 hours before removing from the mold.
The only color I had any problem with was yellow. It probably would have been fine but it never looked very yellow to me, so I mixed in a few drops of food coloring after adding the paint. I figured yellow food coloring probably wouldn't leave a noticeable stain on the driveway the way the other colors might. Hasn't rained in quite awhile - I'm hoping it will wash off...