This classic airmail issue from Paraguay, valued at 20 centavos, was released in 1929 to highlight the nation’s proud export: yerba mate. Printed in a warm reddish-brown shade, the design features a vintage aircraft in flight above the inscription “La Yerba Paraguaya es la Mejor” (“Paraguayan yerba is the best”). Framed by laurel branches, the stamp embodies both national pride and the early era of aviation. With its UPU marking and bold lettering “Correo Aéreo”, it represents Paraguay’s growing role in international postal services. A fine addition for collectors of Latin American airmails and promotional themes.