Communication designers Barbara Hahn and Christine Zimmermann have been collaborating on joint projects since 2004. In 2008 they founded »Hahn+Zimmermann« in Berne. The graphic design agency works in the fields of communication design, information graphic and design studies for national and international clients as well as on independent projects. Since 2007 Hahn and Zimmermann have been researchers at the Academy of the Arts in Berne, specializing in “Knowledge Visualization”. Both give lectures and presentations on information graphics at several professional colleges and universities.

In 2008 Christoph Merian Verlag published their work “Of B and C: Data Visualization Beyond Pie Charts And Bar Graphs”, followed in 2012 by the art project “FAQ – Frequently Asked Questions”, a book.