Last 23rd of May, the Spanish Post made available this stamp featuring the title-page of the Valencia, Joan Joffre, 1514 edition of Celestina. It celebrates the yearly Festival Celestina, which takes place every August since 1996 in La Puebla de Montalbán, and about which we have talked more than once in this blog (here, here, here and here).
According to the description available at the website, the heart-shaped lock represents the impossible love of Calisto and Melibea, while the colour choice (purple) is a reference to the importance of this colour in the Middle Ages.
This is not the first time Celestina appears on a stamp. In 1998, the Spanish Post also issued a stamp devoted to this work.