This feature is present in the F1-type 50-peso banknote, in the G-type 50-, 100-, 200-, 500- and 1000- peso banknotes, as well as in the 100-peso banknote, commemorating Mexico’s 1917 Constitution.
The numbers that comprise the folio gradually increase in size. The first numeral, which is located next to the letter, is the smallest; the subsequent one is bigger, and so on.
On the G-type 50- and 100-peso banknotes, the increasing folio is in vertical position.
50 pesos, G (current design)
images of the increasing font-size folio number on the G-type 50-peso banknote
50 pesos, F1
100 pesos, G (current design)
images of the increasing font-size folio number on the G-type 100-peso banknote