I took the rock chips I liked and arranged them on pieces of medium density fiberboard (MDF). I filled in some of the overhangs with pliable resin and waited until they were set up. Then I spray painted them black to ensure that they looked the way I wanted them to. Then I made molds from them using MoldMax 30 from SmoothOn. The castings you see below were made from an expanding type of foam that expands 10:1 by volume. I used this as I wanted to make sure I got the resin into all of the crevasses. Once the resin had set up (about 15-20 minutes) I took the pieces out and spray painted them with black spray paint from WalMart and drybrushed them with craft paints. The flock is from GF9. I am pleased with how they turned out. I have had several people ask me if I can make them for them. If you are interested, let me know and I can send you one each of them for $15 which would include postage. You can then paint them as desired.