Blue Ribbon Books was a notable American publishing house established in 1930, known for its innovative production of children’s books featuring movable elements, particularly pop-ups. The company is recognized as the first U.S. publisher to trademark the term "pop-up" for its "Illustrated Pop-up Editions." Blue Ribbon Books collaborated with Harold B. Lentz, who was instrumental in the success of their pop-up books. Lentz provided not only the artwork but also the engineering behind the intricate pop-up mechanisms, making these books highly sought after by collectors. Some of the most famous titles produced by Blue Ribbon include The "Pop-Up" Pinocchio (1932) and The "Pop-Up" Cinderella (1933), both featuring detailed illustrations and interactive paper mechanics. Blue Ribbon Books also made a significant impact with their Disney-themed pop-up books, which helped bring classic Disney stories to life through interactive illustrations. These editions included iconic titles such as The "Pop-Up" Mickey Mouse and The "Pop-Up" Donald Duck, which became highly popular among children and collectors alike. Blue Ribbon Books' pop-up editions remain highly collectible due to their historical significance and craftsmanship, marking a key moment in the development of children's interactive literature in the United States. The publishing house is remembered for popularizing movable books in the U.S. market during the 1930s and establishing a lasting legacy in the genre of pop-up books.