Do you use a mold release over a sculpt when using Ultra Call 30? I'm working on a pred mask sculpted out of firm klean klay and am wondering if you use a release on the clay sculpt like say petroleum jelly or pam. I've read that these are used on resin reproductions and I was just wondering if the were used to get the sculpt from the mold cleanly as well. Any info is greatly appreciated. Thanks.