Sally Spray is an author of children's non-fiction books. She studied Early Years Education, then an MA in Children's Literature, and worked as a teacher before becoming an art director in children's publishing. Sally lives in the Cotswold countryside, and enjoys daily chats with her chickens, daughters and sometimes her husband, the illustrator Mark Ruffle. Her mission is to find out loads of interesting, really hard to understand stuff and pass it on to her readers as simply and concisely as possible.

Mark Ruffle was born near Bristol in 1973. He graduated from the University of the West of England with a degree in Graphic Design in 1995.

After leaving college Mark worked as a visualiser, then in 1997 started working for Oxford University Press as an Art Buyer. Mark has been freelancing since 2000 and has enjoyed working for a wide variety of clients including Aardman, producing illustrations for Flash.

He has designed and illustrated web content for the BBC to accompany television programmes such as Hustle, Holby City and Bleak House. Mark works in Adobe Illustrator and is equally happy drawing illustrations for books, packaging, advertising or animation.