Tamper proof label adhesives are pressure sensitive and can be removable or permanent. Permanent tamper proof label adhesives have an extremely strong bond. There is practically no chance to remove it. If anyone tries it, the label breaks into many fragments.
Removable tamper proof label adhesives are easily peelable and can come in three forms:
High-residue adhesives leave a sticky residue on the product’s surface once the label is removed. They also leave a message and/or a distinct pattern that marks that the product has been tampered with. This type of label is usually used for disposable packages.
Low-residue adhesive is used for packages that are not to be disposed of. Once a label is removed, the hidden message containing words VOID or OPENED (or similar) will show up on the surface of the label, and on the surface of the product where the label has been applied. The removed label leaves some residue on the product, not as much as the high-residue adhesive, and this amount of residue can also be peeled off.
Non-residue adhesives are used for tamper proof labels that seal expensive or reusable packages. There is no residue left upon label removal, but the hidden message VOID or OPENED on the surface of the product clearly shows the product has been tampered with.