Partall Film #10 is a water/alcohol-based polyvinyl alcohol (PVA) mold release agent that forms a barrier between parts and mold surfaces that are still curing (green or recently reconditioned molds can be reactive).
Partall Film #10, the original green parting film, is resistant to solvents and styrene yet is water soluble.
Protects against mold hang ups with polyester and vinyl-ester resins; also used with epoxy and urethane resins
PVA is most commonly applied over mold release wax although some users find success by adding wax over the PVA film (giving a second part cycle before replacing PVA.)
Partall Film #10 can also be used as a surface cure agent during gel coat repairs (locks out moisture in the air that inhibits resin cure).