When casting into a plaster mold with latex, does the plaster have to be sealed first?

Will the latex stick into the mold or is a coating of sealer or wax required? Also, when painting the finished latex piece, do you have to seal the latex before or after?


Thank you for any information.When casting into a plaster mold with latex, does the plaster have to be sealed first?
My experience with plaster is that it almost always needs to be sealed except when using clay slip. I use Murphy's oil soap as suggested many places. But, while I work, with latex, I have not cast it into plaster as I paint it on modeling clay and you need to ask a latex supplier because thick latex takes forever to dry/set so you may need unsealed plaster to suck the water out of the liquid.


Edit


I went looking and this site http://www.fxwarehouse.info/Merchant2/me鈥?/a> which explains the process makes it clear the plaster mold must be unsealed.