I decided to make soles for Monster High shoes using the plastic that is melted by heating (more details here). First I made simple wedge soles. I started by cutting the parts of the molds from thin copper sheet lined with packing tape.
Then I used pieces of the same tape to assemble the molds.
Here are the molds filled with hot plastic and waiting to cool down. The molds are attached to a piece of wood with double-sided tape to make sure they stay in correct position.
And here are the finished soles. This pale yellow is the original color of the E-Z Water plastic pellets.
Then I decided to experiment a bit and made molds for soles with separate heels for Nefera. I just modified the pattern I used for the polymer clay soles.
I was actually quite surprised to see that this worked. If it hadn't, I would have just returned the pieces to the melting pot for re-use. These soles are slightly darker than the previous ones, because I was running out of plastic and had to add a previously slightly overheated batch into the pot. Overheating makes the plastic get darker (and serious overheating makes it smoke and smell bad). The correct temperature to use is the lowest in which you can get the plastic to melt. My stove has a scale of 0 to 12 and setting 5 is just right for this.