When holding the 100-, 200-, 500- and 1000-peso banknotes (F-type) against the light, you can see a thread of approximately one millimeter (width) that crosses the note vertically. This thread is known as security thread and is manufactured directly onto the cotton-paper substrate.

100 pesos	200 pesos	Security thread in 200-peso banknote
500 pesos	1000 pesos

Examination against the light

This feature is detected when holding the banknote against the light.