Preflighting Digital Files
by Ronald L. Bertolina
Copyright 2001, Graphic Arts Technical Foundation
Adapted from GATF SecondSight 75, a reprint of an article appearing in GATFWorld magazine.
View an Adobe Acrobat PDF of
the complete article.
Customers used to hand their printers mechanical boards and photos. After reviewing the materials for a few minutes, the printer could usually tell if everything was there to complete the job from prepress to press.
Now a customer will most likely hand over several disks and insist, "The whole four-color brochure is here on these disks. You shouldn’t have any trouble printing 5,000 copies by the end of the day." And when asked if there are any hard copies or color proofs to go along with the electronic files, that same voice confidently says, "Oh, you don’t need to worry. It looked great on my monitor."
This SecondSight introduces the concept of preflighting, a way to discover potential file problems before they tie up time, materials, and equipment and to make sure digital files will indeed image and not crash the RIP. It also provides some checklists that can be used for the preflighting process.
What Is Preflighting?
Preflighting, a term borrowed from the checklist procedures pilots use before taking off,
is a way to make sure digital files will indeed image and not crash the RIP. It’s a
way to discover problems before they tie up your employees’ time—and your
materials and equipment. Imagine imaging six pieces of film or directly imaging six plates
when you need only four!
Preflighting is a process for thoroughly analyzing a designed, digital job for output readiness, regardless of the intended output device. It’s a way to discover problems such as incomplete or missing digital files and fonts, improper or ignored trapping, inadequate bleeds, incorrect page sizes, wrong color breakdowns, extraneous elements, potential banding problems or jagged images before a job is output. Font problems, considered the most troublesome aspect of proper output, alone justify preflighting. The preflighting process can involve software or checklists or both.
Who’s Responsible?
The question of who’s responsible for preflighting can have several answers,
depending on your customers and your operation. This debated issue can also affect who
pays for what. In any event, printers and other graphic arts service providers are best
off if they establish their own standards for preflighting procedures and
responsibilities. Some printers will not promise they will meet a customer’s deadline
until after they have finished preflighting the files.
Printers and graphic arts service providers can reasonably expect file originators to (1) provide complete files that can be run within acceptable RIP times, (2) provide all the information needed to efficiently run the files, and (3) provide a quick means of contact if problems arise.
All file originators, however, may not understand how to strategically construct jobs for efficient output and with print production requirements in mind. They also may not know the idiosyncrasies of the final output devices. Keep in mind that many graphic artists study design principles such as balance, color, unity, space, and proportion, but may not learn about trapping, a preflighting task usually left in the hands of other professionals.
Open communication between the customer, intended output facility, and the printer is paramount, especially concerning the time and money it can take for a job to be output-correct. Who, for example, will make the corrections? Who will pay for them?
Formal preflighting takes time and in some cases the customer may be charged for these services. Preflighting, however, should not start when the customer hands over a disk. Some preflighting should begin with the customer. As part of their preflighting responsibilities, customers should supply hard copy proofs of the jobs along with the electronic files. Customers can also fill out and submit an output request form, and they can follow a checklist that reminds them to include all linked files and fonts on their disks, not just the page layout document.
When customers take on preflighting responsibilities, the process of preflighting becomes a customer preventive activity rather than an error discovery activity on the part of the service provider or printer.
Guidelines for constructing digital files have been published in the Computer-Ready Electronic Files (CREF) booklet available from the Scitex Graphic Arts Users Association (SGAUA). The term "CREF" and the guidelines are the property of SGAUA and the Scitex UK users group (SUK).
Customers need to know their printer’s policy regarding who holds onto the files once the printer has corrected them. This situation is similar to printers keeping a customer’s film flats, mainly because the flats needed to be kept in a controlled temperature and humidity environment free of dust and dirt, but also because the printer often got repeat work from those same jobs.
A note about copyrighted fonts: It is acceptable in the United States for customers to supply all the fonts used in a document to the output facility, provided the fonts were originally obtained legitimately. The output facility’s intention in using them must be restricted to outputting that customer file and not for future use on other customers’ jobs. In other countries, output facilities must obtain their own copies of all fonts used. The legalities of font usage can differ from application to application, and it is necessary for both customers and printers to be aware of the differences. Read the font license agreement from your font vendor.
Electronic files can arrive in several different ways: floppy disks; SyQuest, Bernoulli, and optical disks; Zip and Jaz disks; CDs; and online digital transmission. Disks need to be labeled with the company name, contact names and phone numbers, and should be identified as, for example, one of three, two of three, and three of three. With so much coming from these sources, it is essential for service providers and printers to install and consistently use virus protection software.
Sales personnel and customer service reps (CSRs) also have preflighting responsibilities. They can, for instance, evaluate the completeness of the output request form; make sure submitted disks are undamaged and are readable; make sure laser proofs are submitted with the job; check in-house font availability; check that linked graphics are correct and not missing from submitted disks; find out if a compression program was used but not indicated; and ensure that folders and files are neither disorganized nor unusable. They can spot potential fundamental problems early on to save time and money.
Some of the same preflighting routines can be double-checked during the digital process. It is not uncommon, for example, for the CSR as well as the preflight technician to check the page size so that a mistake one person missed earlier can be caught at a later preflighting stage.
Effective Preflighting
Production Personnel
Traditional image assemblers can be the primary candidates for preflighting because
they understand many of the issues that underlie preflighting and the printing process.
Trapping, historically the responsibility of traditional image assemblers, is now a
preflighting task and a natural transition for these same professionals.
People who are familiar with the various computer platforms (IBM, Mac, UNIX); with illustration, image manipulation, word processing, and page layout programs; and with trapping and imposition software can also make excellent preflight technicians.
Skilled preflight technicians can do more than preflight. They can actually repair, correct, adjust, and manipulate digital files before final output. This can include re-creating often poorly constructed objects (like gradations and blends) in order to speed up output, decrease waste, and improve quality. Preflight technicians can help customers who do not have the expertise to perform their own file repair. File repair is usually charged to the customer since it is not included in the original quote, which is based on a "computer-ready file." Service providers who give their customers digital file construction guidelines (like CREF) can use these guidelines for deciding what is chargeable file repair (e.g., guidelines that were not followed).
A Checklist for "Manual" Preflighting
Preflighting requires attention to detail and concentration, something that can be
difficult to achieve in the hustle and bustle of a production environment. A formalized
preflighting checklist—a step-by-step routine for analyzing digital files regardless
of the software used—can be a great help. (See accompany PDF file for sample
checklist.)
Preflighting Software
The often time-consuming task of preflighting can be greatly speeded up by using
preflighting software. Programs such as Markzware’s Flight-Check and Extensis’
Preflight Pro can assist preflight operators in discovering problems in digital files.
However, no preflighting software can be solely relied upon to catch all problems, and no
current software does file corrections. This still requires skilled operator intervention.
