In her preface, the author's stated objective for the book is to answer the question "How did he do it?". The audience for the book is any person who admires, or is interested in, M. C. Escher's periodic drawings and would like to understand his methods for designing and executing his artworks. As no prior mathematical knowledge is assumed by the author to understand the material presented in the book, it is appropriate for a general audience. As Michele Emmer comments in his review: "It is important that, with this beautiful volume, artists and scientists can look at Escher's original notebooks."