ON-PRESS IMAGING -- Firing on All Cylinders
There are other issues that can factor into the on-press imaging buying decision, beyond those directly associated with costs. Most are of greater potential concern to shops already running conventional color sheetfed presses.
* 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 life expectancy of the laser should be increased, they assert.
With some of the presses, a plate still can be made in a separate operation and installed on the printing unit in the traditional way.
* One cost associated with all types of digital imaging that can get overlooked is the often sizable service contract that generally comes with a purchase. Buyers of pressroom equipment may not be accustomed to dealing with such charges, which are now associated with DI/DOP presses to cover maintenance of the imaging systems.
* While several of the more recent digital press introductions use a conventional offset printing process, the majority of the systems run waterless. If a printer's current operations are all conventional offset, management may be hesitant to introduce this new variable into the plant.
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, and a single CTP system typically can't make a full set of plates in the time it takes to complete such short runs.