Crayon hot rocks: If you have not done this yet, you need to. Simply warm up the rocks in the oven (I did 220 for 10 minutes), then put them on a stack of newspapers (or something else you don't care if it gets crayon in it) and let the little ones go to town. Just remind them it is hot. I have done it with 2 1/2 year olds with no problem. My little lady often brings in rocks for me to "cook" so she can paint them
How To Make Flubber, Glurch and Other Homemade Art Supplies at Home
The first time I made a batch of playdough for my son I was amazed. Amazed that the recipe worked, amazed at how quick and easy it was and, mostly, amazed at how much nicer it was than the kind that comes in a can. Smooth, supple and soft, even months later. If you're still buying dough in a can, I urge you to convert. And there's a whole world of art supplies you can make in your own kitchen - some I've never even heard of like flubber, glurch, gak and oobleck.
put the oven with temperature of 200º preheats - leave the crayons in the oven places and leaves until melting completely, time of about 10-20 min , it depends on the size of pieces of wax - it leaves to cool completely! found on facebook of Kelly Stein