Every piece has different number, it is helpful to control the quantity of hologram stickers and supervise the use of the consumer.
There are two kinds of numbers, one is continuous ( also be named serial numbers ), the other is discontinuous.
We can produce both black numbers and transparent numbers.
The black numbers can be printed by inkjet printer and barcode printer.
The transparent numbers can only be printed by laser marking machines.
Laser marking machine or inkjet printer or barcode printer.
Continuous and discontinuous.
The cost of transparent numbers is more expensive.