A brush-up on digital basics.

This isn’t the first time Ed has focused on digital printing. In Ed #8, he provided you with an in-depth briefing on what it is, how it works and what it can do. What it can do has changed and improved dramatically, but the basics haven’t changed. Here’s a quick refresher.

Unlike offset printing, there is no film, no color proofing, no stripping or plate making in digital printing. There’s no make-ready, no getting ink to desirable levels by running waste sheets through the press and no time-consuming changeovers. This is why color digital printing is much faster and has traditionally been more cost effective than offset in smaller runs.

The advantages of digital printing have only magnified with continued advancements in quality and economics.

Among many types of digital print technologies, two have made great inroads: toner based and inkjet. Toner-based digital print technology is called electrophotography, also referred to as xerography or laser. Color electrophotography toner is made of electrically charged plastic particles, in cyan, magenta, yellow and black, that are transferred from drums to the paper and fused with heat to fix the image.

Inkjet presses print the image by propelling ultrafine droplets on the paper or other substrate at a very high rate. Continuous inkjet printers use electrical charges to guide placement of the droplets on the substrate; drop-on-demand inkjet technologies apply the droplets in response to a signal.

Electrophotographic is the process used in high-end applications—brochures, catalogs, package labels, posters and others. Inkjet historically has been used mostly for high-speed, high-volume transaction-oriented applications such as billing statements, although this is changing with rapidly improving reproduction quality.