Helvetica, "probably the most successful typeface in all of history", made its debut 60 years ago this year. Thanks in part to these sans-serif types, the International Typographic Style, otherwise known as Swiss Style, has dominated screens, advertising and Ikea labels since the second half of the 20th century. You will find it on U.S. tax forms and web pages. Peter Hulm pays tribute to the Swiss Style and looks at its origins, influence and fractious past as Armin Hofmann, one of its most original practitioners, turned 100 on 29 June.