cornstarch clay and a color wheel/mixing lesson

For regular playdough use I'm hooked on the Jello recipe, but when it comes to making things to keep I like a dough that's really smooth and more clay-like. My recipe for cornstarch clay makes a very smooth, slightly sticky white dough that takes color really well. Most recently we used it for a hands on lesson in color mixing. (On the boycraft front, this really worked with Scout since it's (a) very visual and (b) required a lot of smashing and mushing around of clay to get the color mixed in!). Using liquid food coloring you can mix small chunks into a range of very vibrant hues. Here's how we did it:

Mix up a batch of cornstarch clay (recipe's at the bottom). Once the clay is cool, divide into seven equal parts. Form into balls, then use your finger to poke a hole in the top of six of them. Place four drops of food color in each as follows:

• four red drops
• three yellow drops, one red drop
• four yellow drops
• four green drops
• four blue drops
• three red drops, one blue drop

Seal the top of each ball back up and let it sit for 10 minutes (or longer, up to overnight, if you keep them in a tupperware) to let the color soak in a little bit--it just keeps your hands cleaner. Now the fun starts! Smash and roll each ball until the color is evenly mixed and smooth. (I found that the quickest way to do this was to roll the ball between my hands until it was mixed--about a minute--but Scout preferred the smashing method!).

We put them in a circle on a piece of paper and talked about "primary" colors (red/blue/yellow) and "secondary" colors (orange/green/purple). We then cut small, equally sized chunks of primary colors and blended them together to make secondary colors...look, they are the same as the big balls we made with food coloring!

Next, we mixed "tertiary" colors (red-orange, orange-red, orange-yellow, yellow-green, green-blue, blue-violet, and red-violet) by combining small, equally-sized chunks of each primary color with the secondary colors on either side. These made some gorgeous colors!

Now, I don't have a picture of this, but Scout had the best time smashing the colors together in a big, circular rainbow, then rolling all the colors together until we had the most stormy grey color you can imagine. Quite a remarkable experiment!


Cornstarch Clay:

Ingredients

• 2 c baking soda
• 1 c cornstarch
• 1 1/4 c water

Method:

• Combine ingredients in a medium saucepan.
• Cook over medium heat, stirring constantly until it begins to look like mashed potatoes.
• Immediately remove from heat, let cool a bit, and knead to form a ball. (Be careful not to overcook or it gets lumpy and hard).
  

(Recipe is from "Look at Me: Creative Learning Activities for Babies and Toddlers" by Carolyn Haas-Buhai)