In the panorama of Italian philately, stamp collecting, there is a representative case in which an error led to the birth of one of the most sought-after collectibles. This is the Gronchi rosa, a postage stamp issued by the Italian postal service on April 3, 1961, and withdrawn almost immediately from circulation because of a graphic error concerning the geographical map of Peru. In fact, the episode, which became known early on, managed to turn an official postal issue into a cult object for collectors.

The stamp in question was part of a commemorative series of three, printed on the occasion of the diplomatic trip to South America by President of the Republic Giovanni Gronchi (Pontedera, 1887 - Rome, 1978). The initiative, in addition to commemorating the first official trip of an Italian head of state to the South American continent, was intended to strengthen diplomatic relations with three countries in particular: Argentina, Uruguay and Peru.