Just for sport, I made a die the other night from 6061t6511 The deepest details in the cavity were .06" The sheet sample I used was 5052? .020" I tried a .5" panel of urethane, maybe around 60-70 durometer, sort of worked, but the process destroyed the urethane. I tried again with .19" thick urethane, maybe 85 durometer, and got much better results.
I was curious who has played with this, if you can recommend interesting relative websites, and any suggestions on guidelines for this process.