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PDF 101

Jan 1, 2004 12:00 AM


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Several years ago, GATF (Sewickley, PA) reported that 88 percent of surveyed printers and prepress professionals contend with incorrectly made PDFs from their clients — even though 46 percent actually give training on proper PDF file preparation. In 2004, many printers are still coping with problematic PDFs.

AMERICAN PRINTER asked several PDF experts for tips on dealing with PDF files. Following is advice from:

  • Ted Padova, instructor with Total Training (Carlsbad, CA), and CEO and managing partner of the Image Source Digital Imaging & Photo Finishing Centers (Ventura, CA)
  • Julie Jankowski, director of business development, StaffingTools.com (Bloomington, IN), an online prepress testing and training company
  • Sean Hiss, national accounts manager, Enfocus Software (San Mateo, CA), provider of PitStop Professional and PitStop Server PDF software
  • Carl Young, certified Adobe Acrobat trainer and producer of the PDF Conference.

Transparency: The nightmare ends

Transparency is a wonderful tool for designers, but most often a nightmare for their printers. Adobe PostScript 3 RIPs need to be upgraded to handle transparency, and most RIPs in use today haven't had the upgrades necessary to print such files.

Acrobat 6 fortunately enables you to flatten transparency and print files that otherwise cannot be printed on your RIPs. Don't be confused, however, by the “Transparency Flattener Preview” command under the “Advanced” menu. The Flattener Preview dialog box only shows a preview of how flattening transparency affects all other objects in a document. The actual flattening of the transparency takes place when you print the file or save the job as PostScript to a disk:

  1. Open the “Print” dialog box and click “Advanced” to see the transparency flattening settings in the “Advanced Print Setup” (Fig. 1)

  2. When you move the slider to the left toward “Rasters,” all transparency is flattened and vector objects are converted to raster objects for all affected areas

  3. Change the default “Line Art and Text” resolution of 300 ppi to at least 1200 ppi. If you print film at 2400 dpi, the 1200-ppi setting should work well for all low- and medium-resolution printing.

Source: Ted Padova

Rasterizing vector art files

Tell your clients not to rasterize vector art files until the last possible stage of the production cycle, before creating the PDF. Often people convert vector files to JPEG, and later, when the file is converted again, it suffers substantial quality degradation. Suggest that your clients experiment with the lossless JPEG 2000 format, so they don't lose data when images are compressed.

Source: Carl Young

PDF Writer vs. Distiller

With versions of Acrobat prior to 6.0, PDF Writer was an option for creating PDFs. PDF Writer settings, however, are not ideal for prepress purposes. Distiller makes the best type of PDF for prepress.

If you are receiving files, it is important to check what application was used to create the PDF:

  1. Open the file
  2. From the menu at the top, choose “File”
  3. Select “Document Properties”
  4. Choose “Description”
  5. In “PDF Information,” you will see the PDF producer. If it's PDF Writer, have your client distill their PDF using prepress settings.

You can also change preflight settings to flag PDFs made with PDF Writer or other unacceptable settings.

Source: Julie Jankowski

Missing fonts

One of the most common PDF problems is missing fonts. When a font is not properly embedded in a PDF, it will be substituted with Adobe Sans or Adobe Serif, which very rarely yield the desired visual result.

There are several reasons why a font may not be embedded in a PDF:

  • The font was not active in the native application at the time of PostScript creation
  • Font inclusion is not set to “All” in PostScript settings
  • Improper Distiller settings.

You should always embed all fonts when distilling a PostScript file!

You can fix this problem using PitStop Professional:

  1. Choose the “Select Objects” tool

  2. Select “Window,” then “Show PitStop Inspector”

  3. Select the “Text” tab

  4. Select the “Font Picker” button

  5. Select the “Page” tab. This will display the fonts used on that particular page. The “Document” tab will display the fonts used in the entire document and the “System” tab will display the fonts installed on your system

  6. Use the “System” tab to display active fonts on your system. Select a font you would like to embed in the PDF document and select the “Embed Font” check box

  7. Click “OK” to embed the font.

Source: Sean Hiss

Color separations

Color handling has always been a problem when printing separations — especially from programs that don't support CMYK color. Spot colors may need to be converted to CMYK equivalents, and RGB files must be converted to CMYK.

If you use layout applications for printing color separations, you've probably performed these kinds of color conversions from your favorite separating program. Acrobat takes the color handling one step further by not only allowing you to perform color conversion in the “Advanced Print Setup” dialog box, but also by letting you soft proof color on your monitor before printing the job.

  1. Select “Advanced,” then “Separation Preview.” The Separation Preview dialog box shows you the colors contained in the document (fig. 2). If a spot color appears in the file, the color is shown along with the CMYK colors.

  2. As you move the cursor around the page, the cursor position measures the percentage of inks for any given area.

You can also toggle on and off different color values to view individual colors or color combinations. This feature is particularly helpful when printing four-color on two-head presses with two passes.

Source: Ted Padova

Wrong color space

Another frequent problem with PDFs created for print is images or text that start out in CMYK mode are converted to RGB color space in the PDF file.

To fix an RGB image problem in PitStop Professional:

  1. Find the “Select Objects” tool
  2. Select “Window” and then “Show PitStop Inspector”
  3. Choose the “Color” tab
  4. Click the “Change into CMYK” button at the bottom of the dialog box.

To fix an RGB text problem using PitStop Professional:

  1. Use the “Select Objects” tool and select part or all of the RGB text
  2. Find “Window,” then “Show PitStop Inspector”
  3. Click on the “Color” tab to verify the text color space
  4. Select “Window,” then “Show PitStop Global Change”
  5. Find the “Object” tab, then choose the “Color” tab (these are both default selections)
  6. Select the “RGB Range” radio button in the left column. Specify a range if needed
  7. Click on the “CMYK Range” button in the right column and specify a color to which the RGB text will be converted
  8. In the bottom left corner of the “Global Change” dialog, specify whether the change should apply to the current page, a range of pages or the entire document
  9. Click “Apply.”

Source: Sean Hiss

TrueType fonts

It's a myth that Acrobat can't accept TrueType fonts. The real issue is that there are some fonts that don't have Adobe Acrobat embedding rights, but are used — primarily because they are very inexpensive — in the marketplace. As long as you avoid those less-expensive fonts, you should be able to embed TrueType fonts with no problem.

Source: Carl Young

Spot colors

One problem that may plague your workflow — and even worse, your budget — is the accidental inclusion of additional spot colors and plates. It's best to catch these before going to press, where the mistake of printing the unwanted spot color will cost you additional money.

A quick method of checking the number of spot colors before going to press is to use “Separation Preview” in Acrobat:

  1. Open the file
  2. From the menu at the top, choose “Advanced”
  3. Select “Separation Preview.”

You will see a list of all colors set for printing. If there are multiple spot colors, you'll need to convert them to CMYK.

In addition, scrutinize your preflight reports. Be sure to check the plate information for the total number of plates the document will require to print.

If you have to make color changes, it's best to make them in the file's originating application or via a plug-in.

Source: Julie Jankowski

Preflighting and preflight profiles

Another helpful addition to Acrobat 6 is the ability to preflight jobs directly in Acrobat. Preflighting can be performed by the designer before a job is submitted to you or after you receive a file in your shop. If asking clients to preflight jobs, you can create profiles suited for your equipment. It takes a little time to poke around the preflight options, but once your technicians become familiar with creating profiles, it will be well worth the effort.

To create a preflight profile:

  1. Open the “Document” menu and click “Preflight.” The “Preflight: Profiles” dialog box will open
  2. Click on the “Edit” button to open the “Preflight: Edit Profiles” dialog box
  3. Start with “Conditions” in the far right column and select a condition (Fig. 3)
  4. Copy it to the “Rules” column.

If first creating a new profile:

  1. Create a new rule by clicking on the far left icon at the bottom of the “Rules” column

  2. Select the rule and click on a condition in column three. Click the left-pointing chevron to move the condition to the selected rule. You can add as many conditions to a rule as desired

  3. Perform the same steps by creating a new profile and moving rules from the second column to the new profile you create

  4. Once you've created a new profile, it is added to the list in the “Preflight: Profiles” dialog box. You can export your profile, save it to disk or e-mail it directly to a client. The profile file can be hosted on your website as well.

To preflight a file:

  1. Open the document to be analyzed in Acrobat

  2. Select the profile to be used in the “Preflight: Profiles” dialog box

  3. Click “Analyze” and the file will be analyzed against the profile criteria.

Source: Ted Padova

Image resolution

There are two typical problems: The resolution is either too low and creates poor-quality results, or the resolution is unnecessarily high and the files are difficult to pass through your PDF workflow.

If the images are low-resolution, the only way to correct the resolution is to go back to the native application and re-create the image. This may mean rescanning — resolution can't be added to an image.

To correct image resolution that is too high through PitStop Professional:

  1. Use the “Select Objects” tool and choose the image to resample
  2. Find “Window,” then “Show PitStop Inspector”
  3. Select the “Image” tab and the “Resample” sub-tab
  4. Use the dropdown menu to choose between three resampling types and enter the desired dpi
  5. Click “Apply.”

Source: Sean Hiss

‘Convert to Outline’ and ‘Convert to Raster Font’

Avoid “Convert to Outline” and “Convert to Raster Font” operations. Embed the fonts instead. Make sure that your RIP is fully compliant with its PostScript language specifications, and upgrade those that are not.

Source: Carl Young

Working in PDF

Founded in 1990, Nu Graphics, Etc., Inc. (Woburn, MA), is an 18-employee shop that earns $3.6 million in annual sales and handles more than 80 jobs a week. The printer is well versed in PDF. “Eighteen months ago, we were creating PDFs and editing them with Enfocus PitStop,” explains owner Wayne Moda. “But we began asking ourselves, ‘What can manage PDFs and take care of everything we're doing in our shop?’”

“Everything” includes two Heidelberg Quickmaster QMDI four-color presses with Harlequin RIPs, an HP Indigo Ultrastream 2000 digital color press with an Indigo RIP and an Ultrastream 3000.

Evaluating workflow options

Cost and functionality were Nu Graphics' primary considerations in evaluating workflow options. The printer ultimately settled on Electronics For Imaging's (EFI) (Foster City, CA) Velocity OneFlow prepress workflow system. “For what we need to do here — management of PDFs and workflow — OneFlow was the right product,” explains Moda. “And, it can RIP to multiple devices.”

NuGraphics began using OneFlow in May 2003 to convert files to PDF. Staff use drag-and-drop icons to create customized, automated workflows that handle the preflight, trapping, correction, approval, RIP and other stages of the prepress process. Proofs are printed on the HP Indigo.

Moda says the product's ability to create plate files, especially for the Heidelberg presses, has been a major benefit to Nu Graphics. “We're not even using our press RIP any more,” notes the exec. “We're using OneFlow to create various plates for our presses with the [built-in] screening.”

Saving time, creating consistency

OneFlow is said to automate many prepress functions that previously had to be done manually, not only saving labor and time, but also bringing consistency to the small-format shop. The trapping “represents a major savings in time, and we're making fewer mistakes,” says Moda. “The trapping software and settings that we've set now are a lot easier [than before]. Our prepress operators just drop a job into a folder, and it's done.”

With four prepress operators, OneFlow's consistency is “one of the biggest benefits to me as an owner,” Moda explains. “If our operators aren't using OneFlow, everyone is doing something a little bit differently.”

“In the past, we had a lot of problems with font inclusion, going from one machine [for proofing] to another [for printing]. If we didn't catch it, it could cost us $45 and 20 minutes to image new plates. With OneFlow, we know the elements on the proofs are going to be exactly the same on the final job,” says Moda.

For other workflow solutions, see “Real-world workflows” (June 2003).

Real-world Acrobat 6 review

In the Nov. 5 edition of our “InRegister” e-newsletter, we offered a free copy of Acrobat 6.0 in exchange for a review of the latest version. George Denzinger, art/tech director at Spectrum Graphics (Grand Rapids, MI), was the lucky winner, and he gave us this writeup:

“The upgrade from Acrobat 5 Professional to Acrobat 6 Professional is probably one of the most worthy upgrades I've seen in a while… In the Acrobat Professional program, you can preflight and even change the ‘X’ version of the PDF file you're inspecting. I found this very appealing, in case you need to repurpose PDF files for a client, for example. There is also an inspection ‘palette’ within the preflight function that allows you to see just about every individual characteristic of the file. Editing color models is limited, but this is a huge improvement over earlier versions of the software and instantly makes some older plug-ins obsolete…”

To read Denzinger's full review, see the new products section (p. 54). To sign up for our free “InRegister” e-newsletter, visit americanprinter.com.

PDF file-submission system

Jaws PDF Courier SDK from Global Graphics Software (Centreville, VA) lets print-service providers build and deploy a custom-branded, cost-effective PDF file-submission system for their clients. It integrates with browser-based applications for Web-based job ticketing, confirmation, tracking, auditing and billing, and also features client-side Enfocus preflighting and Certified PDF technology to ensure error-free files. Jaws PDF Courier SDK includes support for PDF 1.4 and PDF/X.