Susan Kare’s most significant contribution to the field of typography is the sans-serif Chicago typeface. Designed in 1984 for the Macintosh, it was made to boost screen readability and considered an integral aspect of Apple’s branding for over 20 years until it was retired in 1997, whereafter it was used on the interface of the first four generations of iPods

The Chicago typeface was also groundbreaking in the world of digital typography because unlike other computer typefaces at the time it was not monospaced, this meant that instead of each character being forced to take up space within a specific rectangle, each character could take up as much space as needed allowing them to closely resemble their traditional counterparts. Kare sought to create a typeface that would complement the Macs user friendly design. During the typefaces initial conception, Kare created the characters on a prototype Mac within the constraints of a low-quality display, leading to the font only consisting of vertical, horizontal and 45-degree elements and having no round edge, Kare dubbed this typeface “Elefont” originally because “it was a heavy typeface, and the pun seemed amusing.”. The name Chicago is a homage to Kare’s home city of Philadelphia, whilst Kare was building up Apples font library, her and Andy Hertzfeld, a software engineer at Apple, named earlier font iterations after stops on its commuter train route, like Merion, Paoli, Ardmore and Rosemont however they were encouraged to choose names of ‘world-class cities’ instead. The Chicago typeface was eventually replaced in 1997 with the release of the Mac OS 8 by another sans-serif font, Charcoal.