They will join The Finishing Point, Multigraf, Simply Print Finishing and Watkiss, who are also due to showcase their latest online and offline products for short- and long-run work at the Yorkshire event.
Finishers at the show said they were hoping to demonstrate how printers can add value through a range of finishing processes applications and systems, producing glued and stitched booklets, cartons, die-cut applications and miniature folding.
Peter Jolly, marketing director of Duplo, said: "The interest in finishing is stronger than ever despite, and probably as a direct result of, the current climate."
The company will be showcasing collators, bookletmakers, PUR and hot melt perfect binders, Ideal guillotines and folders.
Morgana is set to exhibit its range of creasers and entry-level folders, while Watkiss will show its one-pass book and bookletmaking systems for both digital and offset print.
Jolly added: "Prices are very reasonable at the moment and companies are realising that they can afford to bring creative finishing facilities in house in order to save money, improve job turnaround times and expand their services."
Northprint 09 takes place from 21-23 April at the Harrogate International Centre, Yorkshire.
Finishers hoping growing demand will lead to successful Northprint 09
Duplo International, Renz, Morgana and Clinical Print Finishers are among the latest post-press suppliers to confirm their attendance at Northprint 09.