This recipe yields enough for two kids to each make a sculpture or two, but if friends are over (as they often are on winter weekends), definitely double the ingredient amounts.
Put out decorative "stick-ons" in little bowls or paper cups. Fun embellishments, as shown above, include sequins, tacks, keys, cup hooks, soda-can tabs, nuts, bolts, washers, and screws. The end piece from a lamp pull-chain makes a nice bell to hang on a reindeer's neck.
A cookie sheet covered with waxed paper can serve as a drying rack (sculptures take a few days to harden).
2/3 cup salt
1/3 cup baking soda
1/2 cup cornstarch
In a small saucepan, mix the salt and baking soda with 1/3 cup of water and bring to a boil.
In a small bowl, combine the cornstarch and 1/4 cup of water and stir well.
When the salt mixture boils, remove it from the heat and add the cornstarch mixture. Stir vigorously for a minute or two to thicken the clay. Spoon it onto a sheet of waxed paper and allow it to cool before working with it.
I could not wait to give this a try and I really had tons of fun testing this out and making mine. I can't wait to get back to school and try this with my Kinder Friends. This was super easy to make but would not be something that I would make with the kids. I had some leftover clay and I am storing it in a container and will see how long it lasts. My best guess is that you would make it the night before you need it at school. The recipe above is enough for two children so you are going to have to make numerous batches in a big pot.