
Light green envelope with typed text in Spanish using black ink. At the bottom left corner, a depiction of an airplane with text, "POR VIA AEREA" printed underneath in white ink. At the top edge, four c.1946 red 1-céntimos stamps depict an airplane flying over Iguassu Falls, Argentina. Underneath, one green 5-céntimos stamp depicting the Brazil-Argentina International Bridge with date May 21, 1947. Overtop, three black ink cancellations dated December 18, 1947 are present.