Prints, photographs, and all sorts of paper ephemera, including baseball cards, postcards, and labels, became important to collectors in the twentieth century. The word "ephemera" is the plural form of the Greek word that means something that lasts a single day. Today the word refers to something that was made to be used for a short time. A label, calendar, or greeting card with an interesting image or associated with a famous name can be as valuable as a work of art.