Digital Color Proofing -- Proof or Consequences

BY MARK SMITH

Like a pit bull on a mail carrier's ankle, there are some issues that just won't seem to loosen their hold on the graphic arts industry. Font-related issues are the best case in point, having caused problems since the earliest days of desktop publishing and still hindering the processing of many jobs today.

Similarly, digital proofing has presented challenges for most of that same time period. There is no solution that is perfect for everyone, so debate has raged about what is the best—or even just an acceptable—approach to digital color proofing. The points of disagreement usually are rooted in the differing needs of individual printers/prepress operations and, by extension, their clients.

After all, this is a subjective process. One level of proofing may truly be acceptable for a particular user and application, but inadequate to meet the needs of another user and the same or a different application.

There are a number of attributes that can be factors in whether a proof is deemed acceptable. Some of the concerns and issues raised recently at industry conferences and in online forums will be reviewed later in this article. What it all comes down to, though, is the level of risk (re: liability) the parties involved must assume by trusting that a given proof is an accurate representation of the printed result.

It's a pay now or, maybe, pay more later scenario. In general, the closer a digital proof comes to matching all the attributes (color, halftone dots, substrates, special colors, etc.) of the printed sheet, the more it will cost. Conversely, the smaller the investment in proofing, the greater the chance that there will be an unexpected result in the printed piece, which could necessitate a costly remake.

An intriguing aspect to the adoption of digital proofing is the high level of resistance among users to making any compromises in order to enjoy gains in process speed, convenience and control. Most people will concede that a level of craftsmanship has at times been sacrificed in the areas of typesetting/page layout and scanning/digital photography to reap these benefits of digital processes. However, any type of quality tradeoff has been a tough sell when it comes to digital proofing.

Halftone dots were the first area of compromise faced by the industry and, to this day, remain a make-or-break feature of digital proofing for many. Obviously, halftone dots are required if the proof is to reveal potential moiré, but even if that isn't a big concern, some printers won't accept output without dots as a contract proof.

Studying Digital Proofing
The variability in what industry companies consider a digital contract proof can be seen in the "Digital Proofing Study Part VI" report, recently published by the Graphic Arts Technical Foundation (GATF) in Pittsburgh. Products from 13 different manufacturers were cited by respondents as the proofing device they "used most often to create contract-quality digital proofs." Kodak (Kodak Polychrome Graphics) headed the list at 22.9 percent, followed by Imation (11.9 percent), DuPont (10.1 percent) and Polaroid (10.1 percent) as the only other proofer makers cited in double-digit percentages. However, Scitex (9.2 percent) and Iris (7.3 percent) were listed separately. This list represents a mix of halftone (dot) and continuous-tone (no-dot) devices.

(For reference, the chart accompanying this article gives a breakdown of the major digital proofing products in the market. Product specifications are available at www.piworld.com.)

Although he recently joined GATF as vice president and director of research, Frank Scott previously was involved in magazine production for more than 20 years, including serving as director of digital development at Time Inc. Based on that experience, Scott doesn't believe the dots/no-dots issue will go away anytime soon. While it can be argued that such issues are not within the group's purview, he notes that the list of SWOP (Specifications for Web Offset Publications) certified proofing systems also includes a mix of halftone and continuous-tone digital proofers.

Proof acceptability comes down to a question of comfort level—with the technology, one's process and suppliers or customers, and the level of monetary risk involved—according to Scott. "A lot of publishers have reached the point where they don't require a dot-based proof for their edit pages," he says. "On the advertising side of the business, though, the proof is the contract. There is a commitment to matching it. If the proof doesn't show dots and there is a problem on-press because of the screening, who is going to be liable?"

The question of dots/no dots really falls more into the category of verifying the mechanics of the process, rather than proofing of color. Other examples include trapping and imposition. These issues may be critical to the success of the piece, but are overshadowed by color concerns.

Pressing Proofing Issues
In the past, proofing systems and prepress operations were sometimes accused of making "pretty pictures" that didn't represent what was realistically achievable on-press. The trend toward merging prepress and press operations has helped bridge the gap. However, the integration possible with having both functions under one roof has raised another issue. Should the goal be to match the proofing system to the press' capabilities, or should the press' output be made to match the proof?

These alternatives recently were discussed in a message thread on the Printplanet.com CTP Pressroom forum. The original posting asked for suggestions on how to deal with a proofer's cyan color donor not matching the press ink, and mentioned switching to a different ink set as a possible solution. One respondent likened that approach to the "tail wagging the dog."

If a shop has standardized its proofing operations on a specific digital system, or if the proofing solution is being dictated by an outside party (customer or third-party prepress provider), matching the press to the proof may seem like a logical solution. One drawback to this approach is that digital proofing technology is still evolving, so a specific product/model will probably be a transitory standard at best. The bigger issue, though, is the merit of risking any negative impact on pressroom performance, given the sensitivity of the process, as well as the investment in dollars and effort required to create an efficient operation.

Depending on how far one takes it, trying to match a proofer to a specific press can raise its own concerns. Such tightly integrated production processes may only be practical if the printer is the sole supplier for its customers. This approach, in effect, creates a proprietary printing process.

Matching analog proofing systems can be an alternative target for digital proofing systems. Despite CTP's rapid growth, the majority of commercial printing still is produced in film-based workflows. Therefore, analog proofers have retained their standing as de facto standards, and digital proofer users typically still also have analog capabilities. Several manufacturers have taken the step of using the same colorants in their digital and analog products to maximize this match.

While the graphic arts community does have a high comfort level with analog proofs, the competing systems vary in terms of how they represent colors. That's why the best solution is to implement official standards, such as SWOP, supporters say. If all steps in the printing process work toward the same goal—an optimum match with an independent standard—then the result will be predictable, consistent color of the highest quality level possible, their reasoning goes.

SWOP is just part of a much larger effort to bring some consistency and predictability to the notoriously variable printing process. The most ambitious is conversion to working in a device-independent color space as advocated by color management proponents. While calibration is a must and color management has its uses, several members of the CTP forum sent up warning flags in response to a recent posting about using ICC profiling/color management to get a better match between a halftone proofer and a press. The upshot was that, in some cases, using color management tools may alter the dots in a halftone proof, thereby compromising the proof's integrity relative to the printed sheet.

At the last Vue/Point conference, the Color Proofing 2000 panel suggested that including color bars in digital proofs should be a standard practice. With more jobs being handed off digitally, panelist Ray Flatt recommended that the industry go one step further and make color bars a standard component of every file. "We need a known point of reference, both in the file and in the proof, that we can hang our hats on," asserts Flatt, of the Gazlay Marketing Group in Kansas City, KS.

The Latest and Greatest
The introduction of thermal halftone proofing devices and materials represented the last major enabling technology to come to market, but product developments have continued on a couple significant fronts.

One is the ability to simulate or actually print specialty colors, including metallics, with digital proofing systems. Like halftone dots, this can be an important benefit for some users, but not a big deal for others. The ideal solution is to be able to proof all aspects of the piece, but the industry has a history of using other conventions to deal with spot colors, such as cutting overlays.

The other major trend in new product development is traditional proofing system manufacturers and suppliers introducing special software and materials for use with general-application printers. These companies are leveraging their color expertise to turn desktop and large-format printers into digital proofers.

Many of these machines are ink-jet devices that use multi-density, multi-color ink sets, which is both a potential benefit and a concern for their use in proofing applications. The standard in ink-jet printers quickly is becoming six-color systems that add light cyan and magenta to the basic CMYK colors, but some offer alternative colors such as orange and green. In either case, the machine's reproducible color range exceeds that of the typical press. That's where the proofing-specific RIPs and materials come in to play.

Shifting gears to broader business concerns, the GATF proofing study offered some noteworthy insights in this area, as well. As a group, the respondents reported that 43 percent of their customers have unrealistic expectations about the benefits of contract-quality digital proofing. Of those clients, 83 percent had unrealistic expectations about digital proofing reducing the price of proofs, and 42 percent had unrealistic expectations for reductions in turnaround times.

(The GATF Digital Proofing Study, Part VI, is available for $200. For more information, visit www.gain.net or phone 800-662-3916.)

While digital color proofing is a rapidly maturing technology, it appears that not all of the questions have been answered quite yet. Still, the capability has become a crucial tool in the arsenal of modern prepress/printing operations.