Spoilage - too high?
Posted: 26 Nov 2006 06:31 am
"Why would the software suggest a spoilage of 648 sheets if the variable is set to 5% or 10%? There's no range that will generate that huge a spoilage."
A question posed by e-mail from a Morning Flight user. Good question, too. The spoilage was for 1,000 catalog sheets, printed 4/4, 2-up. To clarify, spoilage in Morning Flight is all inclusive and is a property of the product. It covers not only setup sheets, but also sheets wasted during the run. The spoilage range for Catalog Sheets is set to High (9%) by default.
There are really two questions here: Why is spoilage so high, and how can 9% produce 648 sheets? That many sheets, 2-up, would seem more like 130%!
The answer to the first part is the low quantity, a press run of only 500 sheets, printed in four-color process on both sides. Are 324 setup and waste sheets per side a little steep here? Maybe. But it depends on a number of factors, not the least of which is "stuff happens." How old is the press? How critical is coverage quality and registration? If it's a relatively simple job, maybe the product should be a Bulletin where the spoilage drops to Medium (5%) and 180 sheets per side.
The answer to the second part is easier. First, that 9% is for 1-color, 1-side. It goes up as the colors go up. And it goes down with the quantity. On 5,000 Catalog Sheets, 4/4, the total spoilage is only 1,080 sheets (600 for 4/4 Bulletins). Pro-rated, that's less than half the spoilage calculated for 1,000.
The 9% figure is relative, it's not an absolute. More than one factor come into play here. But because it's relative, you don't have to manually change the number of spoilage sheets when you change the job quantity or the run configuration. Morning Flight does it for you.
. . . . . Hal Heindel