Tamper-evident cash bags are specifically designed to protect the integrity of the bag’s contents and alert you if someone has attempted to take anything from the bag. Unlike traditional zipper money bags, locking security bags or canvas bank bags, today’s tamper-evident bags have many security features to indicate if a bag has been opened or compromised in any way, either by a thief of opportunity or a professional.
Freezing Attempt Detection
Experienced thieves know that drastic changes in temperature can break a basic tamper-evident seal on a plastic cash bag without damaging the bag. They typically use a can of compressed air to apply freezing cold air directly to the seal. However, modern tamper-evident cash bags are designed with this weakness in mind. In these tamper-evident bags, the freezing temperature of the compressed air activates security ink that reveals a high-visibility message to signal a tampering attempt.
Heating Attempt Detection
Similar technology can also detect if a thief tampers with the plastic cash bag using heat. Along with freezing detection, today’s tamper-evident bags often feature security ink that will activate when it detects heat being applied to the bag, revealing a red ink line or a high-visibility message to indicate that heat was used to open the bag.
Water and Saliva Detection
Using water or even saliva is another common method for thieves to try to defeat a tamper-evident seal. Thieves who have internal access to the cash security bags, such as employees at a bank or cash-in-transit company, will often use their own saliva to weaken the seal of a plastic cash bag, preventing it from closing properly. A tamper-evident cash bag often has a security feature that uses water- and saliva-soluble inks to detect the use of fluids to tamper with the cash bag’s seal. The bag’s seal features a tamper-evident message printed with the special ink, and fluid will smear the ink.
Security Border and Microprinting
A common security feature in tamper-evident cash bags is the use of microprinting along a security border. This feature uses a printed design along the borders of a bag, which can be cut open with a razorblade and resealed. With the microprinting security feature, you can easily tell if a bag was cut open and sealed back up because it is impossible to line up the tiny pattern of a microprinted security border after cutting it apart.
Small Openings Prevention
Plastic cash bags are typically sealed with a small flap with an adhesive that sticks to the bag to keep it closed. However, employees who want to save time and space for their organization will often fold the adhesive flap further down on a cash bag, unintentionally leaving an opening at the top of a cash bag, which can allow a thief to reach into the opening and take cash from the bag. A triple-seal closure — as seen in our TripLOK bag, the most widely used tamper-evident cash bag in the industry — makes it virtually impossible to leave a small opening in the bag that can be later exploited.