A bonding material is described that is well suited to bonding polymer films, such as polyester films, to other substrates. In one embodiment, for instance, the bonding material can be used to bond a polyester film to a polypropylene article. The bonding material generally comprises an adhesive agent combined with a cross-linking agent. The adhesive agent may comprise a carboxylic acid modified polypropylene homopolymer, copolymer or ionomer. In one embodiment, the adhesive agent comprises a polypropylene modified by an unsaturated dicarboxylic acid anhydride. The cross-linking agent, on the other hand, may comprise an oxazoline polymer.