In-line vs. Off-line Digital Finishing: The Eternal Question
With the growth of digital print, lots of consideration goes into designing the optimum finishing process. And with this, lots of ill-considered advice is dispensed!
The first reaction of many digital print vendors is "don't put anything on the end of my press!" This would have been solid info in the offset world. Web offset presses were not designed for short runs, and adding an in-line finishing system makeready to a press makeready could add many hours (if not a day or so) to the process. In-line finishing was quite common in the direct mail world, but you had to have a run of a million pieces or so to make it viable.
The short-run nature of digital presses means the finishing process must be carefully analyzed. So let's look at the in-line and off-line options, and the arguments for each. First, the terms "off-line" and "near-line" are commonly confused. "Off-line" has been used to mean that the starting point of the product is a printed sheet, while "near-line" means that you are starting from a printed roll.
There are advantages (and disadvantages) to each approach:
Off-line and Near-line:
- Flexibility: No doubt about this. Decoupling a finishing system from the digital press allows the press to PRINT with no possibility of a stoppage from a downstream device. Stoppages are not trivial on an in-line system. When behind a digital press, a restart of the finisher with the press can take several minutes.
- When to choose: If your work is mainly short-run AND requires several format/size changes during a shift, then off-line/near-line is the way to go. Keeping a digital press waiting for the finishing system to be made ready is a very poor use of time. Also, if you have to process the work of several different presses, this is the way to go. Last of all, off- or near-line permit good options for future finishing capacity and capability.
- Labor: Most off- and near-line advocates ignore a very crucial component. It takes more people to finish the product this way. And labor is a huge portion of the economics of print today. Having an off- or near-line finishing solution means you need a separate crew to run it. Contrast this with an in-line finishing system that can run with ONE person for both the press and finishing (yes, I have seen this in production).
- Movement: Many people seriously underestimate this piece of the puzzle. How do you get the work from press-to-finishing? What if the binders are some distance away. Off- and near-line require both moving and staging the work from press to finishing, and often that's a lot of paper to move around.
- Integrity: I had a discussion with a customer a while back over why he chose an in-line system over near-line (over the objections of his printer vendor.) His was a high-security booklet operation and he explained that the fewest amount of touches to the work allowed him to sleep better at night.When printed sheets are moved to different devices, things can get out-of-order. Integrity is much better with a printed roll, but an in-line process can produce better tracking and potential recovery of damaged product.
- When to choose: If the press is running a fixed format size, or size changes are minimal, or if the number of "touches" must be minimized, then serious consideration must be given to the in-line route.
However, when planning an in-line system, make sure you consult with someone who has the experience and knowledge to gauge the "fit" of the various components that will be needed. Questions of speed, paper hand-off between systems, and the operating interface between the modules must all be calculated.
There is no "one best method" and you can't choose the finishing workflow that's best for your operation without doing some real homework.