20 Pesos

Pick 64 runs across a six-year window that coincides with Mexico's post-1970 devaluation pressures and the slow unraveling of the Bretton Woods-era peso stability. The Banco de México had taken over its own printing operations well before this series, making it one of the few central banks in Latin America at the time producing notes entirely in-house rather than contracting to De La Rue or the American Bank Note Company.

The watermark is the sole mechanical security feature — modest by the standards of the period, but consistent with the bank's approach across the lower denominations of this run. Forgery of the 20 Peso denomination was documented during the mid-1970s inflation cycle, which likely accelerated the note's eventual replacement.