Firing On All Cylinders

Why put imaging systems on every press unit, when a complete set of plates can be made in a single offline CTP system? We asked the experts.

by MARK SMITH

TAKING STEPS out of a process can increase productivity, reduce variability and lower production costs. That all sounds great, but these gains naturally must be weighed against the investment required to achieve them.

Doing such a cost-benefit analysis for the on-press imaging concept might at first seem to be a rather straightforward calculation. The potential variables in the equation quickly prove otherwise, however. Issues such as integration with existing plant capabilities, markets served and type of press being considered can tip the balance in favor of or against the technology and workflow. What makes sense for one operation may be a non-starter in a different shop.

Technological factors are only part of the reason why the first implementations of on-press imaging were on smaller-format machines. The value proposition of the concept has always centered around quick turnaround of shorter runs, which fits well with the capabilities of smaller presses. These entry-level presses also were well suited for prepress operations and quick printers adding their first real four-color presses, which became the primary target market.

Since computer-to-plate adoption, for the most part, started with eight-up machines geared toward longer runs, this meant the first direct-to-press solutions were primarily being compared to film-based workflows. The associated labor savings and process efficiencies, combined with the lack of an existing printing infrastructure at most early adopters, made it easier to make a case for the technology. With on-press imaging solutions now moving up in format and CTP systems expanding down, the two workflows are becoming more directly competitive.

As a result, perhaps the biggest question potential buyers now face is, why spend the money to put imaging systems on every press unit, when a complete set of plates can be made in a single offline CTP system that has a much lower capital cost? Most of the same benefits claimed by direct-to-press systems also can be achieved by adopting offline CTP production, especially if the comparison is made to an automated platesetter and state-of-the-art press.

Evaluating The Merits

As manufacturers of both stand-alone CTP systems and on-press imaging kits, Creo Inc. and Presstek Inc. are in a unique position to evaluate the relative merits of the two technologies. If anything, one might expect the manufacturers to be biased in favor of CTP machines, since they sell those devices but do not market complete digital presses. However, the market experts at both companies believe a strong case can be made for on-press imaging, both in terms of cost/process advantages and marketing potential.

First, a couple points of clarification probably are needed to put their comparisons in context. Since Presstek holds a registered trademark on the "DI" (for digital imaging) designation, Creo has adopted the DOP (digital offset printing) acronym for its technology. In broad terms, both designations refer to the same class of products.

The range, number and size of the products in the on-press imaging category continues to grow. The key advantage of DOP presses is their potential to support shorter cycle times, says Brad Palmer, corporate vice president of on-press technologies at Creo, in Vancouver.

"This enables the printer to be more responsive to customers and charge more for a higher level of service," he explains.

On-press imaging also lowers the production costs for shorter runs by eliminating platemaking operations, Palmer says. This process simplification, combined with the press operational streamlining possible in an all-in-one unit, make it easier to manage production and respond to job changes, he continues. The net result is faster makereadies, which means the press can be kept running more of the time when producing short-run jobs, he says.

Creo recently issued a revised white paper that makes the business case for digital offset printing. It includes a DOP vs. CTP cost comparison for a sample job, which shows the former achieving up to double-digit per-copy cost savings for runs of less than 2,000 impressions and maintaining at least a couple percent cost advantage for run lengths to 12,000 impressions.

The example in the white paper is based on a four-over-four-color, one-page job printed four-up on a modern five-color press. According to Palmer, the analysis assumes the same processless plates are used in both workflows and the presses have similar automation features. All costs are factored in, including equipment amortization, labor, space overhead, insurance, service contracts, etc., he notes. The analysis reportedly is based on a four-page manual CTP system with an estimated price of $130,000, which compares to $450,000 for the set of on-press imaging systems.

A significant part of the savings from DOP production comes from eliminating the labor involved in offline CTP platemaking, Palmer says. This analysis is based on a manual CTP system, but an automated machine would increase capital costs.

The other part of the savings comes from quicker makeready compared to CTP-based production.

"The on-press imaging operation is integrated into the makeready cycle and it doesn't extend that time any," Palmer says. "The savings result from the digitally perfect registration you get with the DOP press, which means you get to register and color in fewer sheets, saving time and materials costs."

Palmer concedes that the payback model is very sensitive to the particulars of a print shop and how it is operated. For that reason, he believes DOP and CTP will co-exist in the market over the long term—and even in the same shops.

"They serve different niches of the market and offer different economies," he asserts. The real value, he adds, comes from selling the machine's ability to turn a job around very quickly.

DI Streamlines The Process

Stan Najmr, director of DI marketing at Presstek, in Hudson, N.H., comes at the question from a different perspective, but offers a similar assessment: DI's advantages stem from its streamlining of the process.

"DI systems offer all the benefits of CTP, plus fully automated, in-register printing with extremely short makeready times," Najmr says. "All this process automation provides users with a short learning curve and fast entry into the high-quality, four-color print market. The features of DI are especially attractive to firms targeting the short-run, four-color, on-demand market, which requires fast turnaround time, offset quality and competitive pricing."

Don't view a direct imaging press as just an existing press to which laser imaging kits have been added, Najmr warns. "Printers have to evaluate the productivity of the complete system compared to a conventional workflow."

To get maximum benefit from a direct imaging press, you must integrate four components, he says:

• Spooled digital imaging media

• Laser imaging heads

• A unique press design (V-shape cylinder configuration)

• The digital front end.

Since the typical DI press uses spooled media that is fed automatically and can image all colors at once in about three minutes, there's no way plates can be produced offline and then hung on a press in a similar time frame, Najmr notes.

"By eliminating costly and variable steps, the direct-to-press approach offers the most efficient and cost effective workflow," he says.

In most cases, the entire digital imaging kit for a press—lasers, digital controls and cleaning systems—costs less than a comparable CTP device, he says. The resulting cost structure for short-run production, combined with the marketing potential of quick-turnaround service, results in higher margins, he says.

The findings of a recent survey of Quickmaster 46 DI owners conducted by CAP Ventures for Heidelberg, support Najmr's claim. The survey of U.S. operations reportedly found they had an average gross profit margin of 45 percent, which puts them 15 percent up on the industry profit leaders (30 percent gross margins) as identified by Printing Industries of America.

Even given these advantages, Najmr rhetorically asks: What if a printer already has a conventional press and can't afford to obsolete it?

"In the short-term, CTP systems will be successful for that reason," he says. "However, over the next five to 10 years, DI presses—complemented by toner-based digital printers—will become the industry standard. It just makes economic sense. The workflow is faster, easier and more cost efficient."

Najmr does offer one cautionary note, particularly about larger-format presses: "We found that the savings diminish as run length increases because the number of makereadies decrease accordingly," he reveals.

Issues To Consider

What happens if an imaging unit goes down? The manufacturers point out that the duty cycle for an on-press imaging system, over a set time period, is significantly less than that of a CTP system used at anywhere near its capacity. This is because the on-press system is idle during the press run. Therefore, the mean time between failure should be greatly extended and maintenance requirements reduced, they assert

With some presses, a plate can still be made in a separate operation and installed on the printing unit in the traditional way. It may even be possible to image a plate on another press unit and move it to the one with the non-functional imaging system.

A cost associated with all types of digital imaging that can get overlooked is the service contract that generally comes with a purchase. Buyers of pressroom equipment may not be accustomed to dealing with such charges, which now are associated with DI/DOP presses to cover the imaging systems.

While several of the more recent digital press introductions use a conventional offset printing process, the majority of systems run waterless. If a printer's current operations are all conventional offset, potential buyers may be hesitant to add this new variable to their plants. One of the advantages claimed for waterless printing is that it simplifies the process, but it does have its own learning curve.

Similarly, shops that have already instituted a CTP and conventional press workflow may not want to introduce the new variable of on-press imaging into their plant workflows. Both issues may be less of a concern if a printer is thinking about establishing a new division or satellite operation, especially if it is going to be in more of an office building setting.

In the final analysis, the on-press imaging value proposition may come down to how much is time worth? The capability's sweet spot is quick turnaround (often the same day) of short runs (1,000 impressions is a good average). These parameters make it hard for any other workflow to be competitive. There's little opportunity to make plates ahead of time using an offline system, and a single CTP system typically can't make a full set of plates in the time it takes to complete such short runs.

The big question is, how does that business model fit with a potential buyer's operations and customer base? Ultimately, the suitability of on-press imaging can only be determined on a case-by-case basis.