Ed #8 Digital Variables

A revolution is sweeping the mailboxes of the world’s developed countries—a revolution in print communications. A mass medium is becoming personalized, customized, individualized. And the change is presenting new challenges and opportunities for designers, printers and any business interested in reaching out to customers.

What’s behind the change is the marriage of reliable, high-speed digital printing and sophisticated database software, which combine to produce one-to-one marketing using variable data printing, or VDP.

Variable data printing begins with digital printing. That term encompasses a wide range of equipment, from desktop printers to large, sophisticated systems, which rival some offset presses for quality, as well as hybrid systems that combine digital and offset technology. What all of it shares is the ability to reproduce text and images directly from digital data, using desktop publishing programs.

In essence, digital printing technology allows you to connect your computer directly to a professional print shop. You can send a project online directly to a digital press and produce thousands of copies in a single day. But that’s just one of many advantages. With most types of digital printing, there is no film making, color proofing, stripping or plate making; there is no press make-ready, no time-consuming changeovers, and less waste. And because the images that appear are generated digitally, they can most often be changed on the fly, just as your desktop printer reproduces the different pages of a presentation without missing a beat. Digital technology permits quick turnaround, low-quantity print runs. Books and brochures can be printed on-demand, as they are ordered, eliminating the need to print large quantities of materials and then hold them in inventory.

Most toner-based digital printing systems rely on some type of electrophotographic printing technology. Electrostatically charged particles of toner are attracted to areas of the paper that have received an electrical charge. Then the toner is fused to the paper to form the image. In color printing, toners of the three subtractive primaries—cyan, magenta and yellow—and black are laid on top of one another.

In xerographic systems, a light source scans the image and reflects it onto an electrostatically charged photoreceptive drum. The drum passes over a toner roller, and dry or liquid toners are attracted to the charged image areas of the drum. The drum deposits the toners on an electrostatically charged piece of paper or other substrate, and the toner is fixed to the substrate by heat and pressure. The image and any remaining toner particles are then erased from the drum, which is ready for its next image.

Laser printing systems also rely on electrophotographic technology. The artwork is scanned, converted into digital data and then transferred onto an electrically charged drum using either a laser or a light emitting diode. Toners are attracted to the image areas on the drum, which then transfers them to the substrate. Rather than relying on electrophotographic technology, some digital presses use ink jets that “print” using drops of ink applied to the substrate to create the image. Drops leave the nozzle at a rate of up to one million per second, producing a glossy image with a look that comes close to that of a continuous tone photograph. Continuous jet printers use electrical charges to guide the placement of the drops on the substrate. Drop-on-demand inkjet printing applies drops of specially formulated liquid or solid inks in response to a digital signal.

Hybrid technologies combine digital and conventional offset technology. One type of hybrid technology press combines an inkjet or xerographic system with an offset press, combining the low cost of web printing with the ability to print personal information. Direct imaging (DI), also known as digital offset, presses work like a standard sheetfed offset press, but the plates are imaged and prepared right on the machine. DI presses can match the performance of high quality conventional offset presses, including the ability to handle fine screens—in fact, DI presses are sometimes used to provide a preview of how a project will look before it is printed on a large offset press. No system is perfect, however. Although digital offset presses can accept digital data directly, they do not allow for variable data, because once the plates have been prepared, they can only print identical copies of the same image.

While digital and variable data printing have been around for more than a decade, until fairly recently, their use was limited. Printing speeds were relatively slow; resolution and color reproduction were often less than desired, and the software needed to merge personal data with text and images was difficult to manage. If personalization was desired, four-color “shells” were often printed on an offset press and then run through a laser or ink-jet device that applied the personalized data. Large mailings, involving hundreds of thousands, if not millions, of copies are still prepared this way, to take advantage of the low cost of high-volume offset printing.

Now, however, many of the issues that slowed the adoption of digital systems have been resolved. Today’s technologies offer improved resolution and color, and a few types of equipment can even apply spot colors or a clear dry overcoat. Speeds have increased too—some systems can now print thousands of pages per hour, making them suitable for larger print runs as well as smaller ones. The addition of inline finishing capabilities such as folding and binding on some types of equipment makes the systems even more practical. Improved software simplifies production by integrating data management with common desktop publishing systems. Even the papers used in digital printing have been improved with the addition of coated stocks and heavier weights.

Digital printing found its perfect match in the sophisticated databases that allow companies to collect, manipulate and apply increasingly detailed information about their customers. Communicators now have the ability to target messages more precisely than ever before, and they’re going to town with it.

The growth of variable data printing has spawned new terminology. Conventional printing with no variable data is now sometimes referred to as “static” printing. “Personalized” variable data printing means that the name and address is changed, but nothing else. Although examples are fairly rare, the ultimate in VDP is full customization, where virtually every major element of the publication can be varied in multiple combinations.

“Versioning” is what most people think of when they think of VDP. A number of different versions of documents are prepared to appeal to different groups, determined by demographics, income, location, interests or some other characteristic.

The applications are growing by the day. An auto manufacturer sends out personalized newsletters to new owners, with the images determined by the specific model the customer bought. Real estate agents’ mailings include pictures of the houses sold within a few blocks of yours. Mailings from resorts include photos of the activities you’re most interested in. Catalogs feature clothing that’s suited to the weather your area is having this week.

In the future we’re sure to see more such targeted publications, because they work. Like hearing your name across a crowded room, personalized communications cut through the clutter and help establish a different relationship—you’re not just selling, you’re speaking with prospects person-to-person. And while some claims seem inflated, research and experience indicate that personalized communications increase customer retention, the size of the order and response rates—six times over, some sources say. So even with higher per-page costs, variable data printing can make for a lower cost per response—and higher returns from your communications investment.

Before you decide to go variable, however, it’s good to keep a few things in mind. Not all commercial printers are equipped to handle VDP, and compared to conventional static printing, VDP requires a broader range of skills. While software has become easier to use, graphic arts professionals are likely to need the help of information technology specialists to acquire and manage the data required, and at most of the printers that offer digital printing, IT experts are full-fledged members of the production team. And of course, the data must be good. Nothing blunts the impact of a personalized publication more than a mangled name or title.

VDP also may require a new way of looking at costs. Compared to conventional static printing, both production times and costs are likely to be higher—even the toners and inks are more expensive. But trying to compare the cost of VDP to the cost of static printing is like comparing apples to oranges—or rifles to shotguns. Production costs are likely to be higher, but so are responses and purchases, which can make VDP more cost effective. And since VDP allows you to print on-demand, there’s no need to print and store large quantities of copies that may never be used or that quickly become out-of-date. In the long run, it might actually be less expensive to pay as you go and only print the number of publications that are required at the moment, without tying up capital in brochures stacked on a warehouse floor. 

Key elements of the technology may be new to you as well. One of the biggest differences is that most of the systems rely on toners, not inks.

After they are applied, toners are typically baked onto the surface of the paper at a high temperature. If the temperature becomes too hot, however, the toner can fuse and the image can become shiny. Adding a second pass through the press, or printing on both sides of the paper (duplexing), can sometimes remelt the toner and make it look mottled or uneven. For this reason, many experts recommend against using toner-based printing systems to print letterhead stationery—feeding it through a high-heat laser printer might cause your name or logo to lose definition.

Compared to conventional inks, toner is also somewhat more likely to crack when folded, so it’s important to avoid large floods of color or heavy toner coverage on the folds. Using perfect binding rather than saddle stitching will also help to reduce cracking problems. You might have to rethink the way you print black too. In offset printing, color is sometimes printed beneath the black to intensify the tone, but doing the same in toner-based systems will produce a brown tint. What’s more, dry toner-based systems typically cannot print at the high resolutions available with the best offset printing, so the use of extremely fine screens should be avoided. Liquid toners, which have a smaller particle size than dry toners, behave more like conventional inks than dry toners.

Designers should be aware of other issues as well. The electrostatic charge used to attract the toner often varies in strength across sheet, which can make it difficult to control gradations. Since relatively few of the systems available today allow for the use of spot colors, it can be difficult to match corporate colors or to print metallic inks. Keep in mind too, that what you see on the monitor is not what you will see on press—the colors you see on screen are inherently more vibrant and encompass more of the entire spectrum.

While VDP opens new options in communications, it’s best to proceed carefully. You and your printer should match the equipment to the demands of the job—each type of equipment has its own weaknesses and strengths. You want to make sure that the printers you work with are experienced in handling both the printing technology and the information systems needed to drive it. And especially when you’re just starting out, it’s best to keep things both simple and subtle. While it’s possible to personalize virtually every aspect of a publication, large numbers of permutations become more difficult to manage—simply assembling all of the images and reviewing all the options can be challenging. It also appears that the days of boldly calling attention to personalized information are coming to an end. Today, many of the best examples seamlessly weave personalization into the project without flaunting it. After all, the goal is to reach customers, not to showcase your technical prowess.

Having the right paper is important too. Papers used with digital printing should be engineered to work well with toners and stand up to the heat that can be generated during the image fusion process. A strong surface helps to protect against the picking sometimes caused by tackier, waterless inks. A smooth surface helps to hold the toner evenly.

It’s especially important to control the moisture content of the paper, before and during printing. A digital paper typically contains less moisture than conventional offset papers, so there’s less moisture to evaporate through the printed image when the toners are fused by heat. And both temperature and moisture content are critical for the paper to receive the correct electrostatic charge during digital printing.

The paper should be acclimatized in the press room for at least 24 hours prior to printing, and the humidity should be low. In addition to affecting print quality by causing the toner to cake, high humidity can also cause the paper to jam the press. If a ream of paper is opened and not used immediately, it should be re-wrapped to keep it from absorbing moisture. And while some types of equipment can handle it, in general it’s best to avoid papers with heavy textures, since the toner may not adhere evenly or might rub off on the high spots. Always make sure that the paper’s basis weight matches the specifications of the equipment that will be used to print the project.