500 Guaranies Guarani value on reverse - FCO printer

Paraguay's 500 Guaraníes series of this period was printed by François-Charles Oberthur in Rennes at a time when the firm was aggressively expanding its portfolio of Latin American central bank contracts. The "FCO" printer's mark on the reverse distinguishes this from earlier runs of the same denomination produced by other security printers, a detail that matters for completeness in any series collection.

Security is limited to a watermark — no security thread, no fluorescent inks — reflecting the relatively modest anti-counterfeiting specification Paraguay contracted for at this face value.