After this A4 colouring book’s pages were printed, the finishing process at Duplo could start... Duplo's booklet makers will deal with the printed sheets collated or uncollated, and finish the book to an extremely high standing. Once bound, any excess edges are trimmed, resulting in a clean and professional finish. See below the Duplo’s full range of booklet makers that stem from small tabletop booklet maker to high production commercial booklet makers and saddle stitchers.