Principle of a digital printer. Click to enlarge images.
Digital printing is not just one method but many different ones. The common factor is that there is no physical transfer of the image before printing. You therefore gain very rapid make-ready at low start-up costs. However, it is not yet possible to achieve a print quality equal to that of offset – although the technology is developing extremely quickly in this respect.
As digital pre-press production, the digital distribution of information, and cross-media publishing are becoming increasingly common, so, too, is digital printing. The two basic methods are dry and wet, corresponding to copying/toner printing and inkjet printing respectively. The dry toner places high demands on electric charge stability, while the wet toner places high demands on surface tension and other surface properties.
Pros and cons of digital printing
Since digital printing is developing extremely quickly, the pros are rapidly increasing and the cons are correspondingly decreasing. For example, the costs to print medium to high run lengths are continuously being reduced and the print quality is being improved at a high pace as new and improved inks and toners are being developed.
- very rapid intake, since there are half as many steps in the pre-press production
- leaves no paperboard waste
- manages variable data
- small editions can be printed at very low cost
- dry-toner presses are often reel fed, which enables continuous designs (for example long banners).
- printing quality still not as good as offset
- somewhat inferior lightfastness compared to offset inks
- more expensive than offset at medium to high run lengths
- gives uneven gloss (dry toner) or sensitivity to wear (wet toner)
- wet toner gives more difficult colour control
- there is still limited access to inline finishing equipment that fits these machines.
Key paperboard features
Whiteness, smoothness and surface finish are crucial paperboard features for achieving excellent graphical presentation in digital printing, as well as when using other printing techniques. When designing long banners you need a very strong substrate, so paperboard is an excellent choice.