A water vapor permeable composite is disclosed for use in electroluminescent devices. The composite includes polymeric material having a first surface energy, a phosphorescent material dispersed within at least a portion of said polymeric material; and an electrically conductive material on at least one side of said polymeric material. The conductive material has a second surface energy, said the first and second surface energies are each between about 32 dynes/cm and 46 about dynes/cm. The polymeric material has a moisture vapor transmission rate of at least one gram/100 sq. inches for a 24 hour period at 100.degree. F. for a one mil thick barrier.