These crayons are a blast to make and kids go crazy for them! Use old crayon nubs or soak any crayons with paper wrappers in water for a while to make them easier to peel. I use approximately 6 crayons per muffin tin hole. It is best to heat the wax at about 250 degrees in your oven for 8-10 minutes. Check them at 8 minutes. You will want the colors to just to have melted and still be able to see swirls. If you let them cook to long they ruin.
PS - I have an old rusty half dozen muffin tin that I use for this project so I don't have to worry about cleaning the wax ring that gets left behind from these beauties.