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DESPERATELY SEEKING PERFECT PROOFS

May 1, 2000 12:00 AM


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When a printer spends $2,599,950 on a new press, he or she expects perfection in the printing produced by that machine.

When a printer spends $259.95 for an inkjet printer, he or she expects nothing less than the same perfection and-by extension-that the sub-$300 printer should easily make a proof that equals the quality of the more valuable press.

A few years ago, we would have found the same printer investing in new printing machinery and then investing in proofing equipment to support the new press. Prepress proofing exposure systems, processors and staging equipment represented tens of thousands of dollars of hard currency just a decade ago.

How times have changed! You now can visit your local office supply superstore to see photographic-quality prints emerging from small plastic cabinets while the reciprocating zip-zip-zip of the ink cartridge lays down rows of ink patterns that create dazzling images on consumer-priced printers.

So, a printer reasons, if the quality of these prints is so good, I should be able to harness that quality for proofing my multi-million dollar presses. This reasoning is valid. In terms of color gamut alone, even the least-expensive inkjet printers are more capable than any press-and-paper combination. It should be possible to use that extensive color gamut to print a reasonable, if not precise, color proof of the job about to be printed on the multi-color machines in our plants.

It's important to separate the fact that a printer is priced for consumers from its professional-level capabilities. This is simply a reflection of the trend of high-technology to bring professional-grade products at consumer prices. The fact that professional-quality printers can be purchased for a few hundred dollars does not mean that the printer is inappropriate for the graphic arts industry's more expensive tastes.

Need for digital proofing The printing industry hasn't just chosen off-press digital proofing systems. The industry desperately needs these systems to complement the computer-to-plate systems that have cut conventional proofing out of the production process. No longer do we have the luxury of making a proof from the film-because we have no film!

In response, manufacturers of digital proofing systems are working to build proofing technologies that deliver digital off-press proofs that are effective substitutes for the film-generated photomechanical proofs of yore.

Without film, our industry has no choice but to move to an all-digital prepress proof.

As Dave Zwang reported in December's "Good investments," p. 44, DuPont, Fuji, Imation, Kodak Polychrome Graphics and Polaroid are vying for the position of best halftone color proofing. Whether through the use of their own dedicated hardware, or as media for a platesetter, each has released new products that enhance the control and color space. For this article, though, we will concentrate on low-cost color proofing. Products from Canon, Imation, DuPont, Epson, Hewlett-Packard, Scitex and others are filling an important need on the creative side of the equation.

Though the consumer inkjet business was started by Hewlett-Packard Co., Epson has taken a commanding lead in the industry with its line of inkjet printers, devices that have become so popular that one is included with most computer purchases.

With these excellent desktop printers, it is technically feasible to produce a prepress proof that will compare favorably to the printed sheet. And several RIP manufacturers have taken this same technology and applied it to the art of prepress proofing to deliver high-quality proofs from consumer-level inkjet printers.

Among those are Aurelon, iProof, Harlequin, Pixelis and Adobe Systems. Each of these firms has harnessed the power of desktop inkjet printers and corralled the color gamuts with color management software. Each is prepared to change the complexion of color proofing in the new digital world.

print like a press One of the more challenging components of making a low-cost inkjet printer behave like a printing press is the issue of attenuating its performance to match the gamut of colors on a conventional press. The vibrant greens and rich reds of some inkjets are far beyond the gamut of colors available with a standard CMYK ink set on the best glossy papers.

To attenuate "behavior," we can use ICC profiles and color management software to cause the colors in the proof file to match the press gamut more closely. New RIP technology is even moving this capability into theRIP so an ICC profile for the press can be set as the target behavior for printing proofs on that printer. In essence, we are asking the printer to shape its color output characteristics to match the press more closely. The possibilities are impressive and the results can be excellent.

Commercial-quality inkjet printing for the graphic arts is also making it easier for printers to offer a successful digital proof. Scitex/Iris and Imation both use the Iris inkjet printers to make exceptionally nice prepress proofs. The software components of these systems include methods for adjusting the proofer to match the press sheet for a successful match. Both systems also allow the simulation of paper to be included in the proof.

Gray area of proofing When we consider the phrase "contract proof," we must understand the legal component of the phrase. If the customer signs a proof-any proof-that document becomes a legal contract between its maker and the customer.

But, what can a customer expect, and what can a printer deliver relative to any proof? Photomechanical proofs, even when made from the film that is used to expose plates, do not represent exactly what the press sheet will look like. Photomechanical proofs often use brighter substrates than in actual printing and almost always have measurably greater density than a press can deliver to paper.

Over the years, customers and printers have learned to accept proofs as fair representations of the final job, accepting the "understood" strengths and weaknesses of the proofing technology in use.

Those who did not accept this reality were forced to order-and pay for-actual press proofs. Press proofs reveal precisely what the final printing will be, and they remain to this day the only method of making a genuine proof that is not disputable.

Digital proofs are nothing if not an extension of the gray area of proofing, with an off-press medium that simulates the performance of a press while not actually being a press proof. We have substituted a newer digital technology for a photochemical technology. We expect the customer, in the normal course of business, to accept the proof as a simulation of our printing process without committing to the extraordinary costs of press proofing.

Customers simply need to know that we are, as before, showing a simulation of press performance and not an actual press proof. They also need to see that we can print a job to match the proof, as a reflection of our process controls and consistency.

What the printer needs to see in a digital proof is color and appearance, as well as proof that trapping elements and overprint are correct. This is an issue that has been surprisingly difficult for the PostScript generation to deliver. PostScript, from its inception in the mid-1980s, has used an opaque model for all imaging operations, something that made it difficult to show overprint and trapping elements.

PostScript 3, released by Adobe in 1998, finally has operators for trapping within the RIP software, making the process of displaying trap elements simpler on Adobe PostScript 3 RIPs. In recent months, manufacturers of compatible RIP software have responded by adding similar performance to their products.

With this change, it is now possible, without separate trapping software, to simulate trapping on a proof and create precise trapping on final output film or plates with PostScript 3 imagers.

Those using older RIP technologies will need trapping software or in-RIP trapping solutions, such as Scitex's Full Auto Frames software, which has been part of the Dolev imagesetter products for years.

Where are the dots? Changing inkjet proof printers generally do not use halftone dots to make their marks on paper. Instead, they use frequency-modulated screening technologies, sometimes called stochastic pattern halftone processes. As a result, the proofs we see coming from inkjet printers do not have the halftone dots that the final printing will have.

When discussing this non-halftone issue, printers will hear cries of concern from their various departments: "Where are the halftone dots?"

But press operators in most plants that have digital proofing capabilities are content to match color and use the proof as a target for overall color appearance and quality.

Not all customers are demanding halftone dots in their prepress proofs. Most are far more interested in seeing their job in color, comparing the color of the images to their products and sketches, and checking to be sure that their products and services are well-represented by the proof.

Paper simulation Since many jobs are not printed on the best papers, one of the greatest challenges of a proofing system-and this applied in conventional photomechanical proofing as well-is making a proof that accurately represents printing on lesser substrates.

How, in the past, did we explain to customers that the proof looked considerably better than it would on the final printed product because the proofing substrate was much whiter and glossier than the paper they had chosen for their project?

In the ICC color-managed world, there is a rendering intent whose purpose is to simulate the actual paper identified in the creation of a color profile. Thus, when proofing a job for newsprint or other non-white substrate, the proof actually prints the paper color while it prints the balance of the document.

Called absolute colorimetric rendering, this method of color management will yield a more honest proof that represents the final product better than a proof printed on a super-white substrate.

An accurate proof with paper simulation is more valuable than the explanations for the inability of a proof to show the actual characteristics of printing.

The "magic bullet" Though often touted as a magic bullet, color management systems and the application of ICC-compliant color profiles will help to produce quality proofs only if rigorous quality control measures are in place to ensure the press and proofing systems behave as they did when the profiles were made.

Baseline solid-ink densities are a critical starting point for those using digital proofing, and a requirement for success in using color management technologies. Fortunately, digital proofing systems usually have less variability than presses do, so managing quality and consistency for digital proofing is less complex than the same task in the pressroom.

The application of ICC color profiles to proofs can be extraordinarily effective, allowing the proof to simulate any smaller gamut press/paper combination with ease. Some of the latest RIP technologies allow the application of a simulation profile on-the-fly for jobs proofed on a specific press/paper combination.

Harlequin, Imation, Iris, Onyx and iProof all have this capability in their latest RIPs.

Most page layout software today offers some degree of support for color management at print time. QuarkXPress, Adobe PageMaker and InDesign each offer support for proofing with color management.

With QuarkXPress, the most common application used in graphic arts production, color management can be applied while printing, and support is present for simulation while proofing. The real weakness of XPress is the absence of the standard four rendering intents, which allow proofing with paper simulation included. Third-party XTensions for QuarkXPress, like Praxisoft's Compass Pro XT, allow the use of all ICC rendering intents, which yields a better proof than Quark's internal functions.

Adobe InDesign offers support for the four ICC standard rendering intent settings, making that application more color management-savvy than its counterparts, without the addition of software-enhancing plug-ins.

When using these applications, all one must do to make a proof that simulates the press is to print to a proofer with the correct ICC profiles designated in the color management set-up window. QuarkXPress, for example, will apply a press profile as it prints to a proofer if the simulation setting is made in advance.

In such situations, generic ICC profiles are not adequate. Specific profiles that are measured from actual press/paper/ink combinations are needed. Both the proofer and the press must be profiled for color management to be an effective proof simulation method.

One RIP, two processes For digital proofing, we are seeing printers moving to inexpensive and fast inkjet devices, those that can create a four-up or larger simulation in a reasonable period of time. A secondary objective is for the RIP that processes the proof to be the same RIP that will generate the final film or plates.

When different RIPs are used for proofing and imaging, there is some risk that very subtle differences will occur in imaging. These subtle differences can be profound, with the ruin of the final job as the greatest risk. In some cases, different RIP products will make minute changes in the appearance of text, or will cause tiny changes in the halftoning methods used to create images and tints.

Though irregular, these inter-RIP issues are significant and cannot be ignored. But careful control of variables and a watchful eye over the quality of production can minimize the risk of using different RIP technologies for proofing and printing.

We're a digital imaging company serving publishers of magazines and catalogs. We bought one of the first Epson Stylus Pro 5000s in our area. When we saw a show demo, we knew we were seeing the future and bought our first one on the spot. We had been using dye subs, breathing a collective "ouch" every time we had to buy materials (and profiling the ribbons). We were impressed with the results that were possible through careful calibration. We've had to make our own way, to a certain extent.

This new generation of inkjet printers is both amazing and promising. You discover very quickly that results are linked in an interdependence of media, ink, hardware, software and color management. The Inkjet Proofing Discussion Board (www.jerron.com) is dedicated to these factors and those who manage them.

How do offset printers feel about inkjet proofs as contract proofs? In our experience, their response has been mixed. They need a known benchmark. Yet they know that inevitably they will be using other proofs than Matchprints and Approvals. Their customers are pushing them to use the new proofs. Once they actually see good, calibrated inkjet proofs and use them, however, the responses are often favorable.

We routinely send inkjet proofs to large, midsize and small specialty printers, as well as to publishers as both intermediate and contract proofs and randoms. They have been readily accepted, especially after they see a test proofed on both Epson and Matchprint. Printers definitely can run to them and do good work. One major printer asked us to proof a GATF target first so they could examine its characteristics compared to their in-house Approval. No problem.

That having been said, it must be a quality, calibrated proof. Just having fancy paper with a mark on the back doesn't do it. There's a trust relationship with the producer of the proof.

It's also important to have stable media. We settled on more expensive media, but it pays because it's rock solid.

Acceptance comes first from the publisher, the customer, the buyer. Once they are convinced and have the comfort level, they can ultimately dictate the proofs that the printer will run to, or find someone who will. So inkjet proofs are and will be widely used. Probably as color management becomes even more mature, this discussion will fade, like the old debate about traditional vs. desktop typesetting.

Ken Cooper, Vice president of electronic services, Jerron Quality Color (Red Bud, IL).

tales from the front | Ken Cooper, vice president of electronic services, Jerron Quality Color (Red Bud, IL), wanted some information on inkjet papers and inks. He posted a query on the CTP Pressroom at PrintPlanet.com. The response amazed him, and wanting to return the favor, he started the Inkjet Proofing Discussion Board at Jerron.com. The site features users' proofing experiences, discussions on RIPs, color management, proofers, consumables and more.

the case for dots | First presented at the November 1999 PIRA Proofing Conference, "The Value of Digital Halftone Proofing" outlines the advantages and future of laser thermal digital halftone proofing. www.kpgraphics.com/info/WhitePapers/Drupa2000/digihalf.html.

handbook | BRIDG'S (Basic Requirements for International Design & Graphic Solutions) has released its Color Proofing Handbook 2000. Volunteers representing all facets of the graphic arts helped produce the handbook. It covers monitor proofing, remote proofing, inkjet technologies, digital sublimation proofers, laser proofing, electrostatic proofing, photomechanical proofing and more. Fore more information, e-mail BRIDGS2000@aol.com survey says | The Graphic Arts Technical Foundation (GATF) (Sewickley, PA) recently released the results of its "2000 Survey on Digital Proofing." The study documents the experiences of 109 printing companies and service bureaus that have adopted digital proofing. For more information, contact Sara Welsh in GATF's Research Dept., (800) 910-4283.