Centralized color management is essential for multi-channel document processing – it and only it makes possible CI-conformant output on all physical and electronic media.
Until now, the issue of color in document processing was exclusively the purview of print. But in the age of multi-channel processing, color management needs to be redefined. The ever-present need to deliver correspondence that complies with corporate identity (CI) can be met only by a stringent color workflow management process that is available for all communications channels, physical and digital alike (print, e-mail, portal applications, secure mail, etc.). Special channels such as ECM (Enterprise Content Management) systems are included.
The challenge: Unlike printed documents, digital documents are opened by the recipient on different end-devices. But because each device reproduces color differently, the document presentation is also different. Technically it would not be feasible to adjust the color for each and every device. What is far simpler, however, is to build the color spaces that are standard for a smart phone or a tablet right into the output management system (OMS).
Hybrid delivery is a horse of a different color: The documents are created digitally (and transmitted electronically to an external service provider, if needed), but can also be sent via e-mail (or as an Internet download file), or printed and sent in hard-copy form. Here it is also important to use a color space for the electronic document that guarantees high-quality physical and electronic output. The following underscores what is important for color management in both single-channel and multi-channel processing.
Color adjustment for print
Print is a typical single-channel process. Documents made available by the customer often contain different color spaces. The problem is that it is rare for the incoming files to be checked for the appropriate color spaces so that they can be transferred directly to document processing, whose main job is not color adjustment but format conversion and document optimization.
Print is basically about two things: The data has to be “rasterized” and then it has to be sent to the printer engine. Usually this is done in a raster image processor (RIP), which is software (or a combination of soft- and hardware) that converts the data of a page description language (including PCL, PDF, PostScript) into a raster graphic for final output on a printer. These applications usually come with a special color management module, which is needed because only the CMYK color space is appropriate for print. In other words, the data is adapted to the color space of the printer.
Special colors can make color adjustment even more difficult because as a rule automatic adjustment does not produce the desired results.
It usually isn’t possible to use the color management module alone as a separate application. Sometimes data can be exported, depending on the RIP. But for the most part the data is already “rasterized” and “color-corrected” and is difficult to use, if it can be used at all, for output via other channels. The following illustrates the workflow for print output.
Color adjustment in hybrid processing
The situation is different in hybrid delivery. As already explained, it offers a number of different electronic channels in addition to print. This is known as multi-channel processing – even when there are no digital channels in play but multiple printing systems instead, such as roll-fed systems for output and a cut-sheet system for reprints. Even these two printers behave differently with respect to color reproduction. If you now try to use single-channel workflows for multi-channel output, you quickly hit a wall – because the electronic channels cannot use the color management module for print output.
You have two alternatives:
- You don’t use color management at all for the digital channels.
- You implement centralized color management in the output management system (OMS).
The first option is out of the question if all documents must conform to a corporate identity (CI) regardless of the delivery channel. Hence, only the second option remains. It supports additional scenarios such as hybrid delivery. In this scenario the color is adjusted for the e-mail channel at the same time as for print.
Inserts must also be adjusted
The files can also be passed on to an ECM system without the need to make channel-specific adjustments. Should the documents need to be delivered at a later point in time, all channels can be used to produce reliably high quality. However, this principle does not work if the rasterized data from the print output is used for archiving.
Yet another issue is the integration of electronic inserts. They, too, must be adjusted for output quality for each individual channel. Another common problem is that the inserts are supplied by advertising agencies that have no color processing expertise. If the inserts are sent directly to document production without prior review, unpleasant surprises often arise.
First check, then deliver
Furthermore, if in addition to color management you define a uniform working color space (such as RGB), more doors for optimization open. For instance, the PDF-X standard supports the installation of a validator to check at least all external PDF documents. Files that do not meet the standard are automatically rejected. In other words, the supplier can validate documents locally (Adobe Acrobat) before passing them on to the service provider, thus allowing correction of erroneous or non-color-conformant files before handover.
This method is also recommended for hybrid delivery, such as via E-Post. The color specifications are worked out in advance with the external service provider, who then adjusts his channels accordingly to guarantee CI-conformant processing at all times. Because color management has been centralized for all devices and channels, it can be de-activated for print output.
Optimized files for higher throughput
Centralized color management offers another benefit: It affects the file size. For instance, the customer supplies documents for e-mail delivery as print data, i.e., image data (4-channel, CMYK) that is not required for email delivery (3-channel, RGB), but does have an impact on throughput (processing speed). It would be better, and hence more efficient, to convert the data into a working color space (3-channel, RGB) on import into the output management system (OMS), making the file smaller, which in turn boosts throughput and affects subsequent archiving.
Conclusion: Centralized color management is what makes CI-conformant connection of electronic channels to the document and output management system at all possible. New media/delivery methods can be integrated without difficulty, leaving only the effort involved in configuring and maintaining the color management system. Special procedures such as dealing with specific colors are also managed centrally for all channels. Last but not least, optimizing files for higher throughput without sacrificing reproduction quality is yet another reason to implement centralized color management.