Scent of a kitten: the 20 irrefutable theories of book cover design

Do you judge a book by its cover? Designers Jon Gray and Jamie Keenan shared their theories on attracting readers – from cute cats to alluring perfume – at the Edinburgh book festival.

1. Face theory: Research suggests that human beings spend 48.6% of their lives decoding facial communication, so a big draw for a potential book buyer will be the familiarity of a face. The cover of Nick Hornby's Otherwise Pandemonium, for example, uses a cassette tape to create the image of a face.