Abstract: An electroluminescent lamp assembly wherein the basic lamp electrode structure is encased in at least one layer of a primary encapsulant material and at least one layer of a secondary encapsulant material, a layer of substantially transparent polymeric film material, which is thermally stable up to temperatures of at least 300.degree. F., being disposed between the primary and secondary encapsulants. The polymeric film material is bonded to the primary encapsulant using a silane agent to enhance the adhesion thereto. In a preferred embodiment of the lamp assembly a gas suppressant agent is included in the electroluminescent material and the light transmitting electrode thereof has a substantially transparent and infusible coating of a polymeric material having release characteristics on its exterior surface, such coating providing an unbonded contact between such electrode and the layer of material adjacent thereto.