Disclosed are edible film coating compositions of low moisture permeability and their methods of preparation. The compositions comprise cross-linked, refined shellac and hydroxypropyl cellulose (HPC) in a weight ratio of 1:0.001 to 1:2. Highly preferred compositions additionally comprise mono- or di-carboxylic acid adducts such as adipic, succinic, lauric, or stearic acids in a weight ratio of acid to combined weight of shellac and cellulose of 1:33 to 1:10. In the preferred method of preparing, the shellac is cross-linked in a dry, molten mixture with the HPC by heating at 130.degree. to 175.degree. C. for 2 to 15 minutes. The coating compound while molten is dissolved in a food grade solvent, applied to a substrate, and dried. The coating compositions are particularly useful as a moisture barrier in composite food articles having phases in contact which differ substantially in water activity. Effective films range from 0.1 to 5 mils in thickness.