How do fonts change the meaning of a message? What was Comic Sans invented for? Why was Obama's first election campaign so typographically bold? And which font would make you buy one chocolate bar over another?

Michael Rosen is joined by graphic designer, author and the font of all knowledge when it comes to fonts, Sarah Hyndman, to discuss the psychology of typefaces.

Sarah is the author of 3 books, including 'Why Fonts Matter' and 'How to Draw Type and Influence people'. She is also the founder of the Type Tasting studio, which aims to change the way we think and talk about typography through interactive and sensory experiences.

Producer Rebecca Ripley.