It may look like a simple piece of chalk, but it is the beginning of a million activities that take place every day in game rooms, sidewalks and playgrounds. Unleash hopscotch. Sign. Tic-tac-toe. It is the brush that paints portraits, landscapes and still lifes. It's hangman and mazes and puzzles. It is all these things without batteries or screen. As luck would have it, making sidewalk chalk at home is surprisingly simple and makes a pretty cool rainy day activity all yours (with adult supervision).
Homemade sidewalk chalk is easy to make with plaster of paris and something to pour it on. We like the size and weight of the chalk made from toilet paper rolls, but other sized cardboard tubes or silicone molds like those used for candy or baked goods can also be used.
Use duct tape to seal one end of toilet paper rolls. This recipe is designed to mix one stick of chalk at a time to make as many or as few colors as the paint or tilt will allow.
Cut the sheets of wax paper one-half to one inch longer than the cardboard tubes and line each tube with a sheet. Make sure the edges of the wax paper overlap so there is no exposed cardboard inside the tube.
In a sandwich-size plastic bag, combine 1 cup plaster of paris and 1/2 cup warm water.
To color the chalk, add about 2 tablespoons of tempera paint to the bag. Tempera paint is a non-toxic washable paint often used for finger painting. Use as much or as little as you like to create pastels or richer colors, but more paint in the mix will result in weaker chalk.
Seal the bag and squeeze and roll by hand until a thick, uniformly colored paste forms.
Cut a hole in one corner of the bag about a half inch wide. Slide the open corner into one of the prepared cardboard tubes and squeeze the plaster into the tube for filling. Make sure there are no gaps or large air bubbles. Mix new bags of plaster for each color.
Let stand for 24 hours to harden..
Peel the cardboard and wax paper from your finished chalk.
Hit the driveway! This mighty sidewalk chalk is a handy tool to play with, easy to clean, and almost as fun to use as it is to make.
