Efficient Personalised Variable Data Printing
Digital printers already have the equipment needed to produce VDP campaigns, so there’s no great expenditure required to begin offering VDP to their clients; all that they need to understand is the software requirements and the workflow digital signature.
From the hardware perspective, a variable data print set-up looks like a lot like any other digital printing installation, with a digital press, a RIP or digital front-end (DFE) to drive it and whatever inline or offline finishing equipment is needed to turn printed sheets into a sellable product. The differences from normal static print are mostly at the file creation and pre-press stages: the two main software components are the database and the authoring software, though VDP also puts some extra demands on the RIP or DFE.
As discussed elsewhere in this series, the printer doesn’t necessarily have to own a database application, as long as the data needed for the personalization can be extracted and supplied in CSV or Excel formats to use with the master template in the authoring application.
VDP authoring applications come in a variety of types of digital signature online. Some, like PTI FusionPro (recently acquired by Ricoh), are plug-ins to popular professional design and layout tools such as Adobe InDesign or Illustrator. Others are dedicated VDP tools or the printed output part of cross-media production suites; PrintShop Mail is an example of the former, while DirectSmile, XMPie and GMC Inspire are the latter. Vendors of DFEs and/or digital presses also offer VDP creation tools, such as the FreeForm tools that are included with every Fiery controller, or Xerox’s Freeflow software.
Whichever type of authoring software is used, the same thing happens at print time: the customer-specific data – which may be both images and text – is fed into the variable fields in the layout template, according to the business rules assigned to the template. This generates a print stream which is sent to the DFE.
There are a number of different print hand-off formats for VDP, reflecting the history and origins of the technology in high-end transactional print. Some are vendor-specific, such AFP (Advanced Function Presentation) from IBM, VPS (Variable Print Specification) from Creo or Fiery FreeForm and FreeForm 2; some are open formats based on existing commercial graphic arts standards like PostScript or PDF. These include VIPP, an open VDP language from Xerox for output of PostScript files, and PDF/VT, a variant of the PDF ISO standard that is optimized for VDP applications. PPML (Personalised Print Mark-up Language) is another open standard which allows the use of PostScript, PDF, EPS, JPEG and TIFF formats for pages or page components.
Which of these formats is supported will depend on the authoring software. Printer or DFE vendors’ software will, of course, support their own equipment but may also support others, especially the open standards PPML and PDF or PDF/VT. VDP and cross-media software from independent developers usually support the widest range of options.
It’s worth noting that not all the VDP formats are equivalent. The older, vendor-specific ones don’t all support the same level of graphical flexibility, in particular, the use of transparency and layer effects to combine images and variable type. For printers just starting with VDP, this is unlikely to present an immediate problem, but if your plans include producing customized images using variable data text, the more recent PDF and PDF/VT standards are probably better options, though PPML has support for transparency too. PDF and PPML allow previewing of the print file for checking, though the latter requires a dedicated viewer.
The hand-off format also has to be understood by the DFE. Again, single-vendor solutions tend to support their own formats best, though may accept others in addition, typically the open standards. DFEs such as Fiery support all the major formats and standards, giving their users the most flexibility. A feature common to all DFEs that can process VDP work is the ability to ‘cache’ or store and re-use objects that appear in each document so that they do not have to be processed each time. Most of the VDP formats explicitly support this by identifying such elements within the print stream or appending or referencing them as separate items. Some DFEs can also analyze the incoming print stream and identify and cache repeated items automatically to improve performance.