I just found this blog and am so impressed with it I just had to share.Penniless Parenting ... extreme frugality
Homemade Chalk (This is something the kids could help make during the school holidays)
Plaster of Paris
Tempera paint (optional)
1. Mix plaster of Paris powder with enough water to make a wet paste. Add water a little bit at a time. Note that it'll thicken considerably when you mix it. Add enough water that it mixes easily and is relatively wet. No matter how wet you get it, the plaster of Paris will still dry; the wetter it is, the longer it'll take to dry.
2. Add some paint if desired. If no paint is added, you'll get white chalk. If paint is added, you'll get colored chalk. Note that the color of the chalk will lighten considerably once dried.
3. Put mixture into a mold. Crayon molds work fine, as do any non deep molds. I made my chalk in the plastic cover of one of my containers that was approximately 3/4 of an inch deep.
4. Let chalk dry for a few hours.
5. After it hardens somewhat, score it with a knife where you want to break it later. If you don't do this, it's ok, but this step makes the next step easier.
6. Let the chalk finish drying 100%. Overnight is usually enough.
7. Break the chalk into pieces.
8. Give to your kids and watch them entertain themselves!
This recipe is terrific because plaster of Paris is dirt cheap and easy to get around here. I made a nice amount of chalk, and it cost me less than 25 cents.
I find the cheapest place to get plaster of Paris is at hardware store. I can get a 2.5 pound bag there for a dollar. Craft stores charge much more money for this.
Please pop over there and have a good look around, I for one want to know more about edible weeds and repurposing stuff.