there are numbered coupons, movie tickets, and work permits. There is only one for each person. In fact, generally speaking, as long as the number of single products is small, but the overall number is large, those are variable data printing.
variable data printing simply means printing regularly changing contents on the substrate, such as printing consecutive numbers from 1 to 1000 on each card. Regular flow codes on tickets belong to the category of variable data printing. There are many, many specific, as long as you want.
simply put, the number of each card is different, and it also has anti-counterfeiting function