The fracture mechanics of the Blister Test is discussed. The configuration allows the composite junction strength to be simulated by the pressurized fracture of a centrally debonded interfacial assembly. In case of elastomeric adherents the work of fracture is dissipated in the elastic extension of the debonded section. It is shown that this may be expressed in terms of the biaxial stretching of the elastomeric layer. For a given set of material properties, the fracture energy was found to be an exclusive function of the relative extension ratio of the blister formed at the interface. The computed fracture energies and pressure profiles were found to be in close agreement with the experimentally observed values. These observations may have practical implications in the design of viable blister experiments.