I designed and made relief from A drawing in Artcam. I machined the model into Hotblock from modelmaster.
I'm not quite sure what it is, I think A polyester resin of some sort. and made A mold off of it. Then from there wax & cast.
The one I cast in gold is going to be 2 tone so I have to cut the wax in pieces and cast seperately, then weld them back together. I really like the hotblock because it cuts really well and you can go straight to the molding. Except don't use silicon rubber because it reacts with the material. I use the castaldo gold label. If you need some casting done shoot me an email if you want.