Well, as you mention this article I read two days ago because it comes with delay here, I would like to ask something to Mr Usher, as I did not catch it : you show a piece of cardboard with a round hole, but it is obvious that the green blotches are not all roughly round, so my question is : you mention you change the cardboard mask now and then, but do you still make a round hole or ...
Apart from this, thank you for the article and for the one on resin casting.