1 Peso Tesoro Nacional - Blue type

Paraguay's wartime finances during the Triple Alliance conflict (1864–1870) were managed almost entirely through domestic note issues — no foreign credit was available, and the blockade made overseas printing impossible. The Tesoro Nacional printed its own currency in Asunción throughout the war, using whatever materials and equipment were on hand. That domestic origin shows: the engraving is rudimentary compared to contemporary Latin American issues printed by Bradbury Wilkinson or Waterlow in London.

The blue-type designation distinguishes this from other color variants in the P#21 series. Wartime attrition was severe, and surviving examples in any condition are genuinely uncommon — the war killed roughly half the Paraguayan population by 1870, and the subsequent Brazilian occupation saw much of the remaining circulating currency rendered worthless and discarded.