I just had my new gold test stone delivered & thought I'd try it out for you.
About $21.00 delivered.
The underside has an anti skid pad
It's 6" by 3". My first one seems weenie now.
It is easier to get a trace than my old stone.
And the trace is of more uniform quality.
I'm still just playin with this stuff. Lined up above the stone are 10 new 14K wedding bands I bought today with their corresponding trace below.