We decided to make our own heart crayons using older crayons we had lying around. The children participated from start to finish in the process. The first thing that had to be done was peeling ALL those crayons. They were eager to get started and before long we had several children working diligently to remove the papers from the crayons we were going to use.
After we finished peeling the crayons, each child chose the two colors they wanted to go into their special heart crayon. We then had to break the crayon into pieces small enough to fit into the heart-shaped tin. This was harder than you'd think. I didn't think they could do it, as it was rough on my hands, but they were persistent and succeeded. I did make myself a guide that you can see below so I would know which child chose which colors.
We then had to maneuver the pieces around to fit into the heart shape. Sometimes this required a little more breaking, other times they fit perfectly.
After our tin was full we placed it in an oven set on a low temp (250-300 degrees) and kept watch on the process. You just want to see that they are completely melted. Keeping the kids at a safe distance, we removed the tin from the oven and placed it on a countertop to cool completely.
They turned out beautifully. It was so cool seeing the colors blend together, yet stay separate. The one downside we discovered was that they didn't work as well to color with as they did in their original form. I don't know if melting them changed something in their integrity or what. You could still color with them, but the colors weren't as vibrant as I had hoped. However, one can't deny how beautiful they look.