Abstract: Polymerizable unsaturated polyester compositions are provided, particularly useful in the manufacture of multilayer laminates, consisting essentially of(1) a polyester of a polyhydric alcohol and a polycarboxylic acid, at least one of which is ethylenically unsaturated;(2) a monomer copolymerizable with the unsaturated polyester and having a boiling point below 150.degree. C.;(3) an additive forming a film on the polyester surface that inhibits volatilization of monomer from the polyester composition; and(4) a hydrophobic compound soluble at least in part both in the unsaturated polyester and in the film-forming additive that either(a) has an isoprene unit structure, or(b) is acyclic and has at least one ester and/or ether bond; and at least two terminal hydrocarbon groups, each with at least one ethylenically unsaturated group.