In vs. off (line) — A "Fight" to the Finish
However, Kinderknecht warns that one of the drawbacks of off-line finishing is trying to determine the right amount of press impressions for off-line makereadies and not having too much waste or too little product.
"You'll print the total quantity on-press, and each time the job goes off-line, you experience makeready waste. If you go off-line several times, and you haven't calculated enough overproduct, you'll be short on product due to makeready waste," says Barthen. "You don't want to find out that you're short and then have to go back on-press."
"With in-line, you don't have to run additional product; there's no off-line setup, so there's no additional waste factor," explains John Trentman, engineering manager at RRD Direct—another major user of both in-line and off-line finishing systems. "Whereas with off-line, you're generating more waste because you have to produce overruns to make sure you have enough product in the end, after the off-line makereadies.
"You always need overruns, and there's not the overrun issue with in-line," Trentman continues. "But there is also higher waste in makeready when running in-line."
Another attribute of running in-line, according to Trentman, "Once you're up and running, you come up with a product that goes directly into the mail or into a lettershop to be inserted into an envelope. There are no delays with in-line."
Whereas with off-line, the operation is roll-to-roll, then to the finishing line, "so there is a delay," Trentman says, "but even with the delay, off-line is still more economical. With in-line, your press is waiting while the finishing line is being set up, or vice versa, the finishing line is waiting while the press is being set up.
"With off-line, you set the press up and as the product comes off, you put it on the finishing line, which isn't waiting for the press. It's both a makeready and cost savings," Trentman explains. "With in-line, there's a large amount of capital waiting for the other line to get set up. The finishing equipment is either waiting while the press is being set up, or the press is waiting for the finishing line. Both take time to get ready, often an average of two to five hours for either process—and that's a lot of capital being tied up."