Janet and Anne Graham Johnstone illustrated more than a hundred books, which included classic fairytales by Hans Christian Andersen, the Brothers Grimm, J.M. Barrie, Charles Kingsley, a series from the Bible, as well as legends from Greece and Rome and many collected rhymes and modern stories. They drew with a strong line and their use of colour was generally retrained rather than garish but the drawings had a tendency to the sentimental. After schooling during the Second World War they attended the St Martin's School of Art and by the early 1950s the twins had begun to carve a name for themselves as illustrators, working together on almost every picture - Janet developing her skills as an animal and bird painter while Anne concentrated on period costume. They produced a considerable amount of artwork for television programmes (Andy Pandy and The Flower Pot Men) and illustrated Dodie Smith's The Hundred and One Dalmatians.