I have always used Smooth-on. Mold max mainly.
This is an awesome find!! There was not too much to read about it other than a 2 hour pot life which is a little long really. I am more interested in it's strengh for pulls. Also I would check into thickeners.
In any case ... $59.00 for 2 GALLONS!!! WOW! CHEAP!
It says made by Dow Corning. I used Dow Corning stuff, pre-internet. It was very firm, but worked well.