The first principles of a peculiar photographic process were discovered in 1845 by M. Bayard, on the amber and purple surface of a peach. Proud of his peaches, M. Bayard, it is said, was accustomed to mark them with his initials. To effect this he was in the habit of gumming on to the surface his initials cut in small paper characters, and which, under the action of the autumn sun, left their impression on the ripening fruit.
P.S. Yes, this is a joke:-)