Using crayon as an inclusion in polymer clay. I think crayon was the first thing I used as an inclusion about 20 years ago. I need to try them again, clay and they concept of what can be done have changed so much since then!
One of the techniques I've played around with over the past month or two is using crayon shavings as inclusions in translucent polymer cla.
Crayons in clay! (diy) ........ http://mossyowls.blogspot.com/2008/05/crayons-in-clay.html#
a mix of polymer clay, watercolors, alcohol ink, vinegar, baking soda, UV light (and sunshine!), different finishing agents, resist materials
Polymer Clay Tutorial: Faux Pewter Pendants- When the paint is completely dry, make it look pewter using a sharpie marker! Work fairly quickly and fill in the embedded areas of your image using the sharpie marker. Then smudge while wet.