"We started Warm & Wonderful in 1979, selling knitted jumpers from a market stall in Covent Garden. We quickly became known for our sheep sweaters wool jumpers covered with rows of little white sheep, and one proverbial 'black sheep'.

As artists, we've always identified with black sheep ourselves: because of a recessive gene, black sheep are born with black wool in flocks of otherwise white sheep (in a flock of a hundred, there might only be one black sheep!). The sweater seemed to resonate among some other black sheep of the time too: David Bowie, Andy Warhol, Shelley Duvall, Penelope Keith, Anthony Andrews, and, of course, Lady Diana Spencer.

Since Diana's first public appearance in one of our bright red sheep jumpers at a polo match in 1980 she and the design have been inextricably linked. As Princess of Wales, she wore the sweater on several other occasions, eliciting a great deal of press commentary and making the design incredibly popular, not only here in the U.K., but around the world.

We never imagined that our sheep jumpers would bring so many people so much joy, though we always had fun ourselves. Our sweaters have been carried in department stores from New York to Tokyo. They've been worn by grannies, and by NBA all-stars. And the Victoria & Albert Museum even has one in their permanent collection.

After so many years, it's lovely to see that this simple design is making people smile."

Sally Muir & Joanna Osborne