Making Digital Magic
What tricks can help printers handle trapping's complexities?
By Terri McConnell
An in-house prepress and plating operation can provide more precise control over image reproduction and can significantly reduce turnaround times, while offering tremendous flexibility for coping with last-minute remakes and inevitable scheduling changes.
Some printers are electing to bring only the final "output" phase of the process in-house. They still rely on trade shops or color separators to perform all the magic required to transform a desktop packaging design into a plate-ready electronic job file that can be fed into a computer-controlled imaging device.
And it is magic; design files supplied by the customer or agency usually require extensive manipulation before they will image correctly for print. The checklist for prepping a design file is long, and it runs from adding a die line to applying a dot gain compensation curve. One item on the list, trapping, is particularly quality-critical and time consuming.
The term "trapping," as it applies to prepress, describes the precise spreading or choking of color areas to accommodate for inexact registration of inks on press. If and when the printer decides to take on all aspects of the prepress operation and stage his own show, he will find that trapping can be as big a challenge as sawing a lady in half and putting her back together again.
Trapping for packaging requires so much specialized knowledge, in fact, many printers are opting for a Facilities Management relationship with a qualified and experienced prepress service provider. In this relationship, the prepress house oversees the printer's prepress operations and may actually purchase, install, and even operate the film and/or plate output devices located at the printing plant. It is the trade shop's responsibility to feed the devices with production-ready electronic data.
But for the packaging printer who wants to bring prepress in-house via a different route than Facilities Management, the trapping issue remains one of the most important aspects of the prepress digital workflow.