I have been wanting to do this project for some time now. It is a simple way to reuse all of those broken crayons lying around your house.
broken crayon pieces
metal cookie cutters
disposable aluminum baking sheets
old metal baking sheet (optional)
Remove paper wrappers from crayons.
Set disposable aluminum baking sheet on top of old baking sheet. This will help you to keep the aluminum sheet from wobbling when you remove it from the oven. You'll want to use an old baking sheet on the bottom just in case you spill the crayon wax over the sides of the smaller tray either during baking or when removing from the oven.
Place broken crayon pieces onto the tray in any arrangement that you like. I tried to color coordinate so that the colors that melted together wouldn't all end up being some sort of shade of brown and so that they would look good together. Bake in a 325° F oven for 10-20 minutes or until melted.
After the sheen/glossy look on top of the melted crayons becomes matte, cut with the metal cookie cutters.
Plastic cutters will work...sort of. It will be really difficult to get a clean cut and the plastic makes it harder to cut through the hardening wax. I used a plastic cutter for the car shape and will never use plastic cutters again for this. Use metal.
Leave the cookie cutters in place for a few minutes before gently pulling them out.
After the crayon wax is completely hardened, pop the shapes out from the bottom of the pan. Keep the scraps for future use.