A tamper indicating device. A preferred embodiment of the invention provides a backing having a first side and a second side, wherein the backing comprises a first phase and a second phase, wherein the backing has a first level of light diffusion, and when a peeling force is applied to the backing, the backing fractures or internally delaminates and has a second level of light diffusion that is a higher level of light diffusion than the first level of light diffusion; a flood coat applied to the second side of the backing, the flood coat defining a window therein; and a mask applied to the tamper indicating device, the mask being in partial or whole registration with the window in the flood coat.