ON-PRESS IMAGING -- Firing on All Cylinders
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, makes 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.
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, he notes, including equipment amortization, labor, space overhead, insurance, service contracts, etc.
A significant part of the savings from DOP production is the result of eliminating the labor involved in off-line CTP platesetting, Palmer says. It's worth bearing in mind that this analysis is based on a manual CTP system, but an automated machine would increase the associated capital costs.
The other part of the savings is the result of a quicker makeready compared to CTP-based production, he adds. "The on-press imaging operation is integrated into the makeready cycle and it doesn't extend that time any. The savings result from the digitally perfect registration you get with the DOP press, which means you achieve register and color in fewer sheets, saving time and material 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, in some cases, co-exist in the same shops. "They serve different niches of the market and offer different economies," he asserts.