The transition to digital printing impacts production planning, supply-chain management, inventory, and purchasing. For pressure-sensitive
labels, the label material may not need to change. However, printing specifications may need to be revised to permit the digital
process. Quality control procedures will probably change, especially if the label printer assumes more responsibility.
At a major pharmaceutical products company, which ordered its first digitally printed labels in 2004, a certified printing
process eliminates the need for incoming quality inspection, so labels can be delivered directly to the packaging line (Nosco
On Demand Solutions, Nosco). With labels delivered on a just-in-time schedule, and all labels now converted to digital production,
the manufacturer has been able to convert its label storage room to other uses.
One narrow-web digital press especially designed for label printing has four color stations, but can be extended to seven,
which adds orange, violet, and possibly green to the standard four-color process (cyan, magenta, yellow, and black) to enable
reproduction of a wide range of spot colors. Although combinations of these six or seven colors permit duplication of virtually
any Pantone shade specified for a conventional press, special matched colors also are available. In fact, ink cartridges can
be removed and replaced while the press is in operation so spot colors can be changed without causing downtime.
High-quality reproduction relies on a print engine with a resolution of 800 dots per inch and a range of screen options, including
144, 160, 175, 180, and 230 lines per inch ("HP Indigo press ws4500" digital printing press, (Hewlett-Packard Co. (HP)), Atlanta, GA). Computer control delivers crisp graphics, ensures tight registration and eliminates the need for trapping,
or overlapping, colors to ensure full ink coverage. It's also possible to clearly print type in very small point sizes.
Although the majority of digital presses seem to be designed for document reproduction or book publishing, at least two
other companies build digital printing systems capable of printing labels ("Kodak Versamark" high-volume inkjet systems, Eastman Kodak Co., Rochester, NY; "Cromaprint" digital printing systems, Dupont Packaging, Wilmington, DE).
There also are a few digital systems designed to print on corrugated board for applications such as short run transport
packaging, point-of-purchase displays and samples ("HP Scitex FB6700" digital printing system, HP).
Although currently concentrated on labels, digital technology is expected to move into cartons and other packaging formats.
"If you can wrap the material around a cylinder, we can print on it," explains Retha Petruzates, marketing manager for HP
Indigo Digital Printing Solutions.
A growing number of label converters operate validated digital printing systems. Pharmaceutical label printers follow a
validation process similar to pharmaceutical manufacturers and comply with applicable US Food and Drug Administration and
European Union rules such as 21 CFR 211.68 equipment (controls and backup), 21 CFR 211.122 labeling controls (cut labeling and controls), 21 CFR 211.180 records (available for inspection), 21 CFR 820.70 automated processes (validated software), 21 CFR 821.120 device labeling (label integrity), 21 CFR 11 electronic records, and EU GMP 5.33 label quality.
Printing press suppliers typically assist with the validation process. For example, one press supplier supports and expedites
validation efforts by providing reports related to risk analysis, validation plan, installation qualification, operational
qualification, performance qualification, and validation process summary (HP validation pack, HP).
Pharmaceutical label printers have policies and procedures in place to streamline workflow and prevent and detect errors.
In addition to stringent quality control, the inspection process is rigorous, in some cases using a combination of manual
and automated methods to achieve a level of 200% inspection. Pharmaceutical label printers also take great care to secure
computer files, proofs, label material, printed labels and waste.