By this time, the first half started to set up, and I was able to insert aluminum wire hangers into the backs. The hardening first layer prevented the wire from sinking completely through and showing on the front of the finished cast.

Hydrocal heats up rather warm as it cures, and 2 hours is plenty of time to allow set up before removing from the silicone molds. They were so accurate that I literally had a hard time telling which were the originals. (Fig. 7) The original is on top.

Figure 7. Original cast (top) and replica (bottom).

The dealer who sold me the silicone said I should be able to make at least a few hundred copies of each cast without fear of the silicone mold deteriorating.

As you can see, this is not a very complicated process, just a little expensive. However, you truly do get the very best copies with this method, and you can cast many for sale or trade this way. It costs me about four dollars in Hydrocal, and 10 minutes time to make both cast copies of these. I would recommend letting the finished casts set up for at least a week before you ship them. I also like to write on the back of the cast in permanent marker the date it originally was cast and by whom, as well as the location.

I have noticed that some people have painted their casts, but this would only cause some dermal ridges or other small detail to be filled in and hidden.

I hope this helps some of you, and good luck!