This was a one of the mediums we explored in Intro to 3D class. The process was developed by George Mason who was on hand to give us a demo. We made impressions in clay sheets and took a thin cast in hydrocal reinforced with burlap. We then cracked and painted the resulting surface.
This idea came about last minute as I was struggling to come up with objects to create impressions with. I spotted Lynnette's change jar, and the idea was born. While the coins looked pretty realistic after painting, the "water" leaves something to be desired.