What is a tamper-evident seal, and how does it work?

A tamper-evident seal is a label, band, or closure designed to leave visible evidence when someone opens, removes, or interferes with a package. Its purpose is to help users identify whether the product may have been accessed after packing.

For example, a VOID label can leave a visible pattern when removed, while destructible material can break into fragments instead of peeling away intact. Shrink bands can bridge a cap and container so the band must be torn before the package can be opened.

Tamper evidence does not necessarily prevent someone from opening a package. Its main function is to make interference visible, which is why the seal should be positioned across the actual opening point and tested on the final packaging surface.