Pop-up book

A pop-up book is any book with three-dimensional pages, often with elements that pop up as a page is turned. The terminology serves as an umbrella term for movable book, pop-ups, tunnel books, transformations, volvelles, flaps, pull-tabs, pop-outs, pull-downs, and other features each performing in a different manner. Three-dimensional greeting cards use the same principles.^[1] Design and creation of such books in arts is sometimes called "paper engineering". This usage should not be confused with traditional paper engineering, the engineering of systems to mass-produce paper products.