Just made a 2nd batch of crayons using water bottle ice-cube trays for molds (see the first batch HERE). The long ones are made of construction paper crayon bits and feel like oil pastels. You can smudge the color around on the paper when using them. The stubbier, rainbow set was made from misc. crayons. It might be hard to see but there're glitter crayons in the green, blue and purple ones...
Here's a close-up so you can see their size in relation to my hand, which looks a mile long:
Here's before they went in the oven:
Here's after they came out. The plastic trays leave very little residue compared to the aftermath of siliconish ones:
BIG TIP: Before melting the crayons in the oven, put the mold/trays on a cookie sheet. Burning crayon puddles at the bottom of the oven are not nice smelling and I'm hoping they won't be too troublesome to clean off.