This classic colonial-era issue features a finely engraved profile of King Alfonso XII of Spain, used during the Spanish administration of Puerto Rico. Printed in a rich rose-red shade, the design follows the elegant Iberian portrait style of the late 19th century, complete with corner Greek-key ornaments and a clean oval frame. The “1 Mil de Peso” denomination reflects the old Spanish-Puerto Rican currency system used before U.S. rule. These stamps are prized for their crisp portrait lines, varied printings, and significance to Caribbean postal history.