Digital Printing Technology in Use
What comes after computer-to-plate (CTP) on the printing-technology horizon? That’s what Editor in Chief Alicia Orr asked you, our readers, in the September issue of Catalog Success. The answer we’ve heard from many quarters is direct-to-press (DTP), which means means the digital imaging of the plate on an offset press, whereas in CTP, the plate is done off press. As part of a digital workflow, both CTP and DTP eliminate film.
Ira Gold, a digital workflow consultant in Rockaway, N.J., says that DTP has been slow to catch on, “We’re seeing a confluence of digital printing and digital imaging [DTP] technology.”
A recent TrendWatch report, “Direct-To: Are We There Yet?”, shows that 1,100 printers are again looking at investing in DTP technology, while 13 percent of service bureaus plan to buy digital color printing presses. Digital presses bypass plates altogether, sending an image right from the computer to the printing cylinder that makes the page impression.
Mary Lee Schneider, president of premedia technologies at R.R. Donnelley & Sons, explains in greater depth the two basic types of digital color printing technology available. The first uses a web offset press, ink and plates, and the second uses an electrophotographic press, toner and no plates.
Digitally driven DTP on web offset presses is a popular solution with printers because the digital technology is basically the same, lacking only the film. Even though plates are expensive, digitally driven presses are still cost-effective because make-readies come out quickly, and ink is less expensive than the toner used in plateless printing. But you can’t really use this technology to personalize because you have to stop the press and change the plate manually. “You can’t change the image as you’re running it; it’s static,” she says.
The other digital technology is the electrophotographic press. Using imaging technology very similar to that available in color copiers, these digital color presses are plateless and use toner rather than ink to paint images on paper. Schneider explains that “every time the imaging cylinder comes around, it gets a new charge for a new image. It picks up toner, paints [it] on the page, that image is wiped clean and a new one is laid down for the next impression.”