Printed Security / Anti-Tamper labels are simply silver foil self-adhesive labels which, when removed from the item they are protecting, leave behind a tell-tale foil pattern saying "VOID" and therefore eliminating their re-application. Typical uses are on sensitive electronic equipment, computer cases, calibrated equipment, medical supplies, medical samples, important letters and parcels, computer data storage media, police evidence bags, DNA samples, alarm systems, shut off valves, tool and equipment marking, light sensitive films, photographic material, important luggage and documents, quarantine items and areas.