Turtleback Books are prebound, hardcover editions of books. The high-quality binding significantly extends the life of the book, resulting in dramatic long-term cost savings. Turtleback Books are primarily intended for libraries and schools. The durable bindings exceed Library Binding Institute standards and stand up to the heavy use associated with libraries and classrooms. All Turtleback Books are guaranteed for workmanship and quality of materials for the life of the book.