Plaster of Paris and tempera paint poured into paper-lined cardboard tubes and left to set into chunky chalk.
What You’ll Need
½cupwater
2tablespoonstempera paint (per color)
1cupPlaster of Paris
Plastic zipper bag
Toilet paper rolls or paper towel rolls (cut in thirds)
Parchment papercut into 7-inch squares
Duct tape
Plastic tray or art mat
Optional: flexible silicone molds
Directions
Cover your work surface, because this gets messy.
Line each cardboard tube with a square of parchment rolled up, and tape one end shut with duct tape.
Open the zipper bag like a bowl; add ½ cup water and 2 tablespoons tempera paint and mix. Add 1 cup Plaster of Paris, close the bag, and knead into a paste.
Cut off a corner of the bag and squeeze the paste into a tube. Tap the tube on the table to release air bubbles. Do the same for the other colors, or fill silicone molds.
Leave to set for a few hours or overnight.
Remove the tape, then the cardboard, then the parchment.
Use right away, or first let it dry completely for 1-3 days.
Notes
Safety: NOT edible. Adult measures and mixes the dry plaster: don't breathe the dust (a mask helps), and never put plaster down the drain; throw extra in the trash. Plaster gets warm as it sets; never cast hands or fingers in it. Older kids (about 6+) can knead the sealed bag with supervision.