- Plaster of Paris or Egg shells.
- Tempera Paint (yes – good old poster paint!). You can use either the liquid or powder versions.
- Old bowls or pots for mixing – we use empty tin cans or yogurt pots.
- Molds –
- Have fun choosing! You could make small chalks with ice cube trays, big fat toilet roll or kitchen roll chalks. Round yogurt pot chalks. Or use popsicle or plaster of paris/play-doh molds for something different. Shaped silicone baking trays can also be used. I think plastic egg cartons would work well too.
- Spatula or old spoon.
- Possibly needed – Wax paper and/or petroleum jelly. Duct tape. Tin foil or film wrap.
|Science tip :
Plaster of Paris is a chemical that reacts with water and heats up to pretty hot temperatures that could burn you. For this reason, do NOT allow your children to poke their fingers in the chalk mixture when mixing or pouring. You can find a science lesson plan that looks at this reaction here. But, so you don’t worry, Plaster of paris is non-toxic so the finished chalks are safe for the children to handle.
Put 2 or 3 tablespoons of your paint into a bowl and add a cup of water. Mix, then begin adding the plaster of paris slowly, mixing as you go. You probably need to check the instructions on the packet to get a better idea of how much to use, but my packet said add until all the water was absorbed! I kept going until I ended up with a thick custard/cake batter type mix.
|Tip : Don’t pour any leftover mixture down the drain – it could well block it. Pour leftovers into an old container that you can bin – or combine leftovers to make a handprint of your child.|
No plaster of paris? How about using eggshells instead? There is a nice document here with step by step instructions and a lesson plan. You are going to need about 6 egg shells per stick of chalk. Sounds like an excuse for a cake to me!