I'd like to mimic this faux tortoise shell material:
Ideally I need the material to be like a thin layer of plastic (probably less than 2mm).
I tried using clear epoxy resin + colors, and I almost got satisfactory results (at least for the first try):
But by the time the resin was curing, the colors were all mixed together, and the final result was a single color. So I guess I need to find another way of doing it.
Any suggestions? I was thinking about using acrylic colors on a thin sheet of plastic, and then using clear resin over it when the colors are dry.