Letter Rain was made from advertising posters that Irwin and his wife scavenged from around the East End of London. He then ripped them into fragments, and reassembled the pieces as an abstract collage. Some of the fragments are reversed, others are the right way round. Individual words and letters are clearly legible in the upper half of the work. Further down, the deluge of letters subsides into a haze of pale fragments through which faint traces of letters are just visible.