Rebound25 silicone rubber ( I used the double mixing method = 1part A to 1 part B mix in a mixing cup, then mix into a second mixing cup. This method helps make sure the two parts are fully mixed.
Smooth-Cast 320 for the castings (320 is harder than the 300 & it allows you to tint the resin.)
Black Urethane casting tint for the smooth cast (allows you to see the layers)
Ease release for the Mold (Once you have the mold completed, you should coat it with ease release
Well when I go to put 2 pieces together and if they don't line up, I just stretch the foam to make it line up. This rarely happens though. I had to stretch the foam on my bicep and the side is curved and does not look the way it's supposed to.
Are you talking about the seams from glueing 2 pieces together? IF so, I normally use a very sharp blade lay it flat on the foam and cut the excess off. Sometimes I wait for the glue to cool down a bit and wiggle the excess glue back and forth until it rips off. The glue has to be hardened just a bit before I do that though so it doesn't smear all over the foam.