In 2007, London’s Edward Barber and Jay Osgerby were named Royal Designers for Industry, Britain’s highest design accolade. But the honor comes with responsibilities as well. Barber and Osgerby were asked to evaluate classroom furniture for a new secondary school being opened by the Royal Society of Arts. “To be honest, we were pretty startled at what is actually being used in schools today,” Osgerby says. Not only were the chairs “poor, substandard things,” he says, but they were constantly break-ing and having to be replaced. Obviously, a new design was needed. Classroom observation and a review of ergonomic studies made it clear that the ideal student chair would include some sort of movement. “If kids can actually move while they’re learning, it massively improves concentration,” Barber says. The eureka moment came when they thought of an angled skid that would permit a subtle rocking motion and also accommodate a forward-leaning posture, ideal for focused work at a table. But that was only part of the challenge. “Having found the right angle,” Osgerby says, “the next thing was, how do we make this chair pass all of the hugely stringent testing requirements for today’s commercial, contract, and school use? That was the harder part.” After two and a half years of development with Vitra, Tip Ton debuted in Milan in April. Here, the designers describe some of the key details of their modern rocking chair.