摘要 |
Sheets used to indicate when tampering has occurred are described. Such sheets are composed of envelopes with generally thin cross sections containing compressed resilient cores which expand upon envelope breach. Expansion of the resilient core results in an obvious visual change to all or some of the envelope surfaces. Such envelopes may also contain a translucent liquid which greatly aids in amplifying the visual changes such envelopes may exhibit. Embodiments may take the form of applied labels, adhesive tape, wrapping paper, mail envelopes, bottle caps, document enclosures, blister packs, etc. Applications include not only signaling tampering but decorative and other applications as well. Processes for fabrication of embodiments are also described.
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