“The pencil is the ultimate tool for the transfer of ideas from mind to paper,” says Edward Barber, one half of the acclaimed design duo Barber Osgerby. The creators of the fêted 2012 Olympic Torch and founders of Universal Design Studio—the design and architecture practice behind the newly-opened Ace Hotel in London—continue our On Design series by lauding the humble pencil. “With the pencil, you’re never 100% committed to what you’re drawing,” explains Osgerby of today's functional subject. “You can change it, erase it, color in with it.” Known for their roguish designs such as the Tip Ton chair for Vitra, the pair met at London’s Royal College of Art in 1996 and set up their eponymous design studio. They have since been commissioned by furniture-makers Flos and B&B Italia and fashion houses Stella McCartney and Louis Vuitton, and were asked to design the chairs for Oxford’s Bodleian Library expansion, only the third chair to be commissioned for the institution since 1602.