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September 2004
Up, Up and Away: Preflighting Your Documents
When you submit a document file to us, our first step is to examine it
in a process we call preflight, a term borrowed from aeronautics. Before
beginning a flight, aircraft pilots run through a standard checklist to
be sure the plane is airworthy and ready for flight. Similarly, we inspect
your file against specific criteria to qualify it as ready to enter the
production workflow.
Before prepress became digital, "preflight" consisted of reviewing
mechanicals - the artboards used to make film or photomechanical press
plates - for quality and completeness. Preflighting a digital file amounts
to the same thing: checking the file to be sure all required elements
are present and that no mistakes have been made in file assembly. The
checking can be done manually or with software tools.
Raster image processing
The ultimate goal of preflight is to ensure that the file can successfully
complete raster image processing. This process turns a vector file into
a high-resolution raster image. In other words, raster image processing
translates the digital information about the appearance of the document
page (the vector file) into pixels and a bit map (the raster image) that
can be understood by the output device.
Raster image processing can fail in two ways. First, the file may not
complete processing. This could be due to missing elements such as fonts
or graphics; corrupt fonts, graphics or data; errors in the PostScript
code; large file size; or other reasons. Secondly, the file may complete
processing but the resulting output may not be correct. A font substitution
may have occurred; line or page endings may have shifted; or too many
press plates may be produced.
Overview of preflight
Whether preflighting is done manually or with software, it involves four
basic steps: selecting the appropriate preflight criteria for the job;
checking the file against the criteria; if necessary, fixing problems
found in the file; and releasing the file into production.
Although the printing specifications of the job determine the exact set
of preflight criteria we use, there are some things we check in all files.
These include:
* a hard copy for comparison
* the presence of all required elements (fonts, graphics, vector and raster
images)
* appropriate color space and number of ink colors
* resolution of raster images (images captured from scanners, digital
cameras or files creates by paint programs) and presence and quality of
clipping paths
* color space and fonts used in vector images
* size of document
If your file cannot pass this first level of preflight, we will return
it to you with information identifying the problems and ask you to fix
them before resubmitting the file.
When to preflight
According to the Graphic Arts Technical Foundation (GATF),
the top ten problems in digital files are:
1. missing fonts
2. incorrect traps
3. incorrectly specified colors
4. scans made in the wrong mode
5. improper page settings
6. unlinked graphics
7. inadequate bleeds
8. lack of a laser proof
9. missing graphics
10. image resolution too low or too high
Most of these problems are incorporated into the file by its creator;
the rest result from preparing the file to give to us. This suggests that
files should undergo preflight at least twice before they are submitted
to us - during file build to check the document creator's progress, and
just prior to submitting the file for print. Preflighting while the file
is being built will eliminate incorrect trapping, incorrectly specified
colors, scans in the wrong mode, improper page settings, inadequate bleeds
and incorrect image resolution. Preflighting just prior to file submission
will eliminate missing fonts, unlinked or missing graphics and lack of
a laser proof.
While it is possible to preflight manually, software tools for preflight
are readily available and fairly simple to use. Some page layout programs
have preflighting tools built in. For example, Adobe InDesign(tm) preflights
documents and identifies problems with linked graphics, fonts, color profiles,
and other key document information. The Collect for Output feature of
Quark XPress gathers images, though it does not gather fonts or provide
any information about the files. Adobe PageMaker(tm) 6.5 includes a plug-in
called Save for Service Provider that copies the document, all linked
image files, fonts, and other files required to print your document. It
also prompts you to locate folders containing linked files, thereby helping
you overcome the problem of missing links.
As important as preflight is just prior to file submission, it will not
help with problems created during file build. For preflighting during
this stage of document creation, dedicated preflight software is useful.
Some programs use pre-programmed or user-defined parameters to check a
file; others will automatically correct common file problems and identify
errors that cannot be corrected automatically. Preflight software may
be either a plug-in or a standalone program operating independently or
in background mode.
The best-known name in preflight software is MarkZware's FlightCheck(tm).
In its version for printers and service bureaus, the program can be set
to check over 150 separate items that could potentially keep a file from
successfully completing raster image processing. A Results screen lists
all problems found as well as a possible remedy.
MarkZware also offers a version for graphic designers and document creators
called FlightCheck Designer. It is a lighter version of FlightCheck Professional
that inspects documents for colors, fonts and images. You set the preflight
parameters by using Ground Controls. For transmitting the file to us for
output, FlightCheck Designer collects the document, images and extensions;
screen and printer fonts; compresses the file; and includes the Ground
Control settings.
If you would like to try a demonstration of FlightCheck Designer, we have
a limited number of CDs with a trial version of the program available
at no charge to you. Just call <here insert the name of your CSRs and
sales staff> at <here insert your phone number> to reserve your
CD. We will be happy to mail it or deliver it to you.
Vocabulary
Bleed - the placement of lines or images so they extend beyond the edges
of a page. Pages are trimmed to the bleed, so the ink must extend past
the trim marks on the printed sheet.
Cropping - defines the precise area of an image that is to appear when
it is reproduced. A simple analogy is using scissors to cut the edges
of a photograph, leaving only the desired area.
Crop Marks - lines that define the area of an image that is to be cropped.
May also be used in place of "trim marks" that show where the
sheets will trim after the document is printed.
PICT - a file format for defining bitmapped object-oriented images on
the Macintosh; often used as a preview for EPS files. PICT format is not
recommended for use in files intended for separation.
Preflight - The examination, verification and attestation of a document
prior to going to print.
RGB - Red, Green and Blue, the standard color model used for monitors
and televisions. This color model should never be used when creating documents
for print.
Spot Color - a color printed in an ink of a specific color, rather than
creating the color by combing CMYK inks.
Vector - the mathematical description used to create lines by defining
the start and end points as well as the formula for the line between the
two points. Vectors are used to create graphic elements. Vector images
can be scaled to any size without image degradation.
Idea Corner
When you are creating document files, it is important that they be error
free - in structure as well as content. The following is a list of suggestions
for creating problem-free document files.
Before you begin:
* Select the color palette and fonts for the job.
* Collect the images you will be using.
* Select the color space (either CMYK or spot color).
* Select the page layout software to use.
As you are building the file:
* Set the page dimensions.
* Save the job to a folder designated for it.
* If using FlightCheck Designer for preflight, set the Ground Control
to be appropriate for this job.
* Preflight the file several times during file creation.
* Correct errors as FlightCheck finds them.
To prepare for file submission:
* Preflight the document again.
* Print a hard copy from the file. If the job prints in more than one
color, print a composite and color separations.
* If using FlightCheck Designer, use the Collect Job function to collect
and package the file for transfer to us.
* Make a backup copy of the file for yourself.
* If using media (CD or diskette) to submit the file, remove everything
on the media that does not pertain to the job. Label the media with your
name, the file name and the date.
Tips & Tricks
Here are some things to remember during file creation that will promote
the successful printing of your file.
Document mechanical specifications
* Document size equals the finished (trim) size exactly.
* Color space is set at either process (CMYK) or spot.
* Spot colors have been specified by PMS number, not selected from a chart.
* Unused colors and style sheets have been deleted.
* Unused elements have been removed from the pasteboard.
* Bleeds have been extended by 1/8th inch beyond trim line.
* Hairline rules are at least 0.2 point
Fonts:
* Fonts of different weights and styles have been selected instead of
assigned attributes from the style menu.
* The document contains all PostScript or all TrueType fonts.
* If custom kerning or tracking was applied, the tables are available.
Raster images:
* Color space is CMYK, grayscale or duotone.
* Effective resolution is 300-400 dpi for photographs.
* Effective resolution is minimum 1200 dpi for line art.
* Images are positioned correctly in their picture boxes.
* File formats do not include PICT, GIF, JPEG or other low-resolution
or compressed images.
Proofing:
* Files have been output to laser and proofed for typographical errors,
correct color separation, line endings and page breaks.
Q&A
Q. I submitted a file that passed the first level of preflight. Why are
you now telling me it needs to be fixed?
A. During the first level of preflight we check for errors in the file
that we consider "fatal flaws" - problems that we either aren't
equipped to fix (such as missing fonts) or are too risky to fix (such
as altering a color space). A file that doesn't pass the first level of
preflight does not meet our file submission standards and consequently
is returned to you for repair and resubmission.
If the file passes the first level of preflight, it still might not be
ready to enter production, but the problem can be fixed by us. An example
of such a problem is a color that is not trapped correctly, or a page
layout that hasn't allowed for bindery (folding, drilling or coil binding,
for example).
Before we undertake any file repair, we will notify you of any extra charges
and time delays and get your authorization to proceed.
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businesses. With cheap postcard printing services, consider all the postcards
you have seen with other advertising venues and what custom printing catches
your attention the most. The next time you receive a promotion in your
mailbox in the form of a cheap postcard printing keep it and study it.
Figure out what the postcard is selling and why they are creating it this
way. By studying this postcard, you can think of ideas for your marketing
project.
PRINTERS
-- Current Postcard jobs available for bid Postcard
projects.
Other services: Printing
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advertising material, Printing Service,
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Company, New-York-Brochure-Printing,
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vs Digital Printing, Printing
Relationships, Font Printing, Online
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Workflow
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