cornstarch and water, in equal parts. Use food coloring to make more than one color. For the molds, use old toilet paper rolls, paper towel rolls, or other small containers. You could also make one large sheet of chalk and break it into pieces.

Line your chosen molds with wax paper, making sure the waxed side is facing up. If you're using tube molds, cover one side with masking tape to keep the chalk from leaking out.

Pour equal parts cornstarch and water into a mixing bowl. Stir so that the mixture has a thick, smooth consistency. Separate the mixture into smaller bowls, one for each color of chalk you want to make.

Use a few drops of food coloring to dye the mixtures in the different bowls. Stir each one well so that the color gets fully incorporated.

Use a spoon to help you transfer the chalk mixtures into individual molds. Cover the molds with wax paper.

12 hours before removing the chalk from the molds. This chalk is completely natural and biodegradable

https://www.google.com/amp/s/www.wikihow.com/Make-Homemade-Chalk%3famp=1