I could tell you all the educational reasons for making soap crayons—children’s learning should be experiential, experience with art should be as varied as possible, following a recipe utilizes math concepts, making something that you can use builds self-confidence and self-sufficiency, having a brand-new experience along with an adult adds adventure and models coping—but the truth is just that soap crayons are fun. You’re in the bath, so you’re supposed to be getting clean, but you’re drawing! With color! But the crayons, they’re soap! So you’re still getting clean!
Who would not have fun attempting to wrap their head around that?
About a cup of grated soap. You can buy soap flakes (I’ve never tried this with glycerin soap, but I can’t see why it wouldn’t work), but it’s also really fun to collect those funky motel soaps and use those, or even to use a cup’s worth of the odds and ends and last bits of bars of soap that nobody really wants to have to use when they’re showering.
2 tbs of hot water. The water should be pretty hot, because you’re trying to melt the soap a little so that it will absorb your color, but the amount of hot water is so small that I generally still let my small daughters stand with me and stir. I let them climb crazy-high into trees, too, and use the hot glue gun, though, so make your own decisions.
Liquid food coloring. As with dyeing dried pasta, you want to use the cheap food coloring here, the little squeeze tubes of liquid food coloring that you can buy at the grocery store, perhaps, NOT your expensive professional-grade gel food coloring.
Mixing bowls and mixing spoons, one large set and enough small sets for each color of soap you want to make.
Pour one cup of grated soap into your large bowl.
Add your two tablespoons of hot water, and quickly mix it in.
Divide the mixture up into your small bowls, then add in the food coloring to dye it. I generally let my girls do their own colors, and they both have a heavy hand with the food coloring, but I find that between 10 and 15 drops of color makes a nicely-dyed soap. Use fewer drops for a lighter tint.
You have to stir the mixture again to mix in the color, but as soon as you’ve stirred it enough that you’re not going to get food coloring all over your hands, feel free to pick up the mixture and begin kneading it by hand. When it starts to feel stiff, as if it’s trying to re-solidify, roll your crayons out like fat little logs. These will be primitive-looking, so you won’t be able to do anything too fancy or use cookie cutters on them or anything, but they will be functional.
Functional as in coloring all over the wall behind your bathtub, that is, so feel free to throw a dash of mildew remover on in there, as well.