Definition of: digital printing

All printed output from a computer is technically digital. However, the term refers more to printing finished pages for brochures, journals and booklets from the computer rather than using an offset printing press and commercial printer. Although digital printer systems do not compete with high-speed newspaper and magazine presses, it is expected that these "analog" monsters will become all digital in time.

Mechanical Steps Are Eliminated
Digital printing eliminates numerous mechanical steps in the conventional printing process, including making films, color proofs, manually stripping the pieces together and making plates. Instead of cutting and folding printed "signatures" to put the pages in order, software sorts them in memory and prints them in the correct sequence.

Ready for Binding
After printing, the output goes directly to next-stage equipment that can staple, 3-hole punch or bind the paper and even turn it into postmarked packages for the mailroom. Millions of invoices, documents and booklets are printed on large digital printer assembly lines every day.


Definition of: DI press
(Digital Imaging press) A four-color offset press that exposes the printing plates on the press itself. Unlike a traditional offset printing press in which the plate processing is done externally, either via exposure to film or via computer-to-plate (CTP), the DI press loads blank plates and images them automatically.

Registration is improved because the plates are loaded onto the machine before they are imaged. In addition, DI presses are waterless and do not require continuous ink-water balancing as do traditional offset presses.

First introduced by Heidelberg in 1993, DI presses provide faster prepress time for short runs, although they are increasingly being used for longer runs.