Customers talk of their experience of moving their printing services to GPC

In 2005, the Guardian heralded a new era in national newspaper journalism by changing from the traditional broadsheet format into the slimmer, full-colour Berliner. Here's how – and why – we made the switch

The proof's in the printing: since the change to the Berliner format in 2005, the Guardian and the Observer have been the recipients of many awards for design, production and sustainability