Meet the collaborators: Bob and Roberta Smith

Bob and Roberta Smith - one man but with two names - is a painter and sculptor from London. He has a number of works in the Tate collection and was one of the British artists chosen to produce poster images for the 2012 London Olympics.

Bob and Roberta Smith has been partnered with Paa Joe, a coffin-maker from Ghana for the BBC's Collaboration Culture project.