Abstract: A sealable package for pharmaceutical and other products which will immediately reveal the presence of tampering. The package consists of a sealed envelope of thermoplastic film having a printed outline in which the sealing of the package is performed at the printed outline. After sealing, the film is shrunk tending to inflate the sealed area because of entrapped air. Should the package be ruptured the inflation is lost. Should the package be cut at the sealed area, it is impossible to reseal the package without a visual indication caused by irregularities in the printed area.