Packaging films, sheets and blown or molded hollow bodies

Packaging films, sheets, blown or molded hollow bodies consisting essentially of a substrate of thermoplastic material and a water insoluble coating on the substrate consisting essentially of a dispersed phase of polyvinyl alcohol dispersed in a continuous phase of a water insensitive polymer that is incompatible with the polyvinyl alcohol, in which the coating is derived from the coating of the substrate with a composition formed of an aqueous solution of a polyvinyl alcohol containing at least 90% vinyl alcohol moieties and a latex of a water insensitive polymer that is incompatible with the polyvinyl alcohol, in the ratio expressed by weight of dry solids of between 0.4-3 parts by weight polyvinyl alcohol to 1 part by weight latex polymer, in which, until the final stages of drying the coating composition on the substrate, the polymer latex constitutes the dispersed phase in the continuous phase of aqueous solution of polyvinyl alcohol, while inversion takes place during the final stages of drying whereby the polyvinyl alcohol becomes the dispersed phase in the continuous phase of the polymer to provide a polyphase coating.