This is the first study to report on the effects of the individual components and blends of an emulsion breaker package on dynamic film and interfacial tensions, film elasticity and diffusivity. These parameters were then correlated with the demulsifier performance. The measurements were made on systems of known crude oil, water and emulsion breaker chemistry. Results indicate that good demulsifier components must create low interfacial and film elasticity, high film diffusivity, high interfacial activity, and low dynamic film tension.