In the following phase of technical evolution of security seals a consequential numbering was added to the name or logo of the producer. This numbering was reported on shipping documents and allowed the receiver to control if the registered one was the same that appeared on the seal he was receiving.
The introduction of the combined codes logo / numbering guaranteed that a unique and unrepeatable device was used.
In new seals, the head corresponds to the lead seal. On this head ( that can be in many different shapes) is impressed the logo. From this moment, security seals become sure like identity cards!
So, we can say that the main difference between lead seals with impression
of the logo and new seals with consequential numbering, consists in the fact
that lead seals only show who the consignor is, while new seals, thanks to
the numbering, can be checked out to verify the correspondence with the
number reported in the shipping documents.
