A file that can be prepared and viewed on-screen, by anyone, anywhere, is a powerful tool in the arsenal
of print production. The Portable Document Format (PDF) is just such a file. PDF files give a good
impression of how the page will look upon output; however, keep in mind that merely generating a PDF
will not fix a poorly constructed page. To ensure its suitability for print, take it a step further and make it a
PDFx-1a file—a focused subset of PDF designed specifically for reliable prepress data interchange—which
can help you realize the full potential of this flexible and efficient file format. PDFx-1a file format is the
preferred file format of the RR Donnelley Digital Solution Center.
File Format Guidelines
Accepted File Formats submitted directly to a Digital Solution Center
- Preferred file format – PDFx1a
Page Construction
File Size – Build single pages. Build all pages to trim size, and extend the bleed 1/8 inch beyond the
document page preferably on all sides or at the very least at head, foot, and front.
Cropping – Trim box (geometry) must be set. Media box, Art box, or Bounding box must be exactly one
inch larger than and set relative to trim size. Output with crop and registration marks turned on, and set
the offset to at least 12 points (.1667"). Any exceptions must be communicated in advance.
Orientation – Build all pages at the same orientation and right reading. Pages must display with the head
of the page at the top of the display. Any exceptions must be communicated to the RR Donnelley facility
processing submitted pages.
Resolution – Continuous tone images meant for high-resolution output should be set to an effective
resolution greater than or equal to 266 ppi. For nested Raster data, the CT resolution should be 300 dpi
(11.81102 dpmm). LW resolution should be 2400 dpi (94.48819 dpmm). Running resolution settings out to
the 5th decimal for dots per millimeter will eliminate the risk of introducing artifacts when pages are
rendered through some Ripping Systems. Consistent resolution within a job is required.
Total Density – Total CMYK overprint densities should not exceed 300‰. Fade off tones should equal a
3-4‰ dot size.
Type Safety – Leave a safety margin of 3/16 inch for type and other elements not intended to bleed.
Shingling requirements and/or instructions should be provided in advance.
Files received at an RR Donnelley Digital Solution Center (DSC) must be accompanied by a composite laser
proof. If separations are not provided, mark composite lasers for color breaks and spot color usage. Mark
“for position only” (FPO) graphics with “FPO.” PDF / PDFx-1a received at a DCS must be single-page only
and undamaged. Include page folios in the file name. This makes it easier to identify which document to
process for a specific page (see File Naming Guidelines).
All component files and resources (linked EPS and TIFF images) must be embedded. Embedded raster files
must be in composite TIFF or EPS format. Do not place a pre-separated element in a page that will be
output as composite.
Note: Nesting EPS files within EPS files can cause errors. Placed DCS files containing raster data with
non-compliant output resolutions can cause artifacts. These situations are not recommended in files
intended for print.
Set continuous tone images meant for high-resolution output to an effective resolution greater than or
equal to 266 PPI.
ZIP and JPEG (maximum quality) compression may be used in images.
OPI (Open Prepress Interface) is allowed for assets stored at a DSC where RR Donnelley has provided the
low-resolution placement files.
To create a good PDF file from an approved application file:
- Print PostScript to file from the application file.
- Convert to PDF or PDF/X using Acrobat Distiller.
The following are not allowed in the PDF/X specification:
- JBIG and LZW compression
- Department Security
- Embedded Scripts, Actions, and PostScript fragments
- Pre-separated pages
- Customer transfer curves, halftones, halftone phases, and rendering intents
The DSC can provide application assistance and Distiller job options to facilitate PDF / PDFx-1a creation.
Fonts – Do not "menu-style" your fonts. These styles may not have matching printer fonts available and
may not print correctly. For effects such as bold or italic, select a bold or italic font.
Type and Rules:
- All typesetting should be done in an application that will retain the vector properties of the text.
- Typeface size and geometry will greatly affect reproduction and the ability to maintain print registration.
- Avoid fine serifs, small lettering, and small artwork.
- Avoid (100% key only) overprint type and hairline rules less than .007 inch or 1/2 point.
- The key type should overprint the background free of C, M, Y drop out.
- Avoid 100% four-color type. (This would equate to 400% total density which is noncompliant)
- Reverse lettering should be carried in the areas of the illustration that will offer maximum contrast between the reverse type and the images.
- Reversed type, 2, 3, 4 color type, and reversed rules should not be less than approximately .014 inch or 1 point at the thinnest part of the rule or character.
- When type prints in a heavy 4 color background, the underlying colors should be spread or choke as needed for better register control.
- Gray type (black type that is less than 100%) should be set to knockout so as to maintain the gray tone. Avoid "gray-on-gray" situations where gray type is surrounded by gray background color. If densities are similar, the gray text will blend into the background and appear as if it has disappeared.
- Exporting a PDF from InDesign is not recommended. Composite fonts (also known as CID or "Identity-H" fonts) have been known to have problems from time to time. It is best to avoid them. If a customer accepts files from advertisers which contain composite fonts, or export PDFs from any version of InDesign which converts all fonts to the composite format, there is a risk that the fonts will not image correctly.
Trapping:
- To avoid bleed into small reverse type or rules and to create proper abutment of elements, the customer or file supplier is responsible for trapping between colors, borders, rules, etc.
- Pages should be trapped as the page creation software allows.
- Pre-existing chokes/spreads are retained in CTs, Tiffs, and Raster EPS images that may be placed into a desktop layout document.
- Typically, in a composite color workflow, overprints and knockouts are retained in files created by desktop publishing software packages like QuarkXpress and Adobe InDesign. Chokes and spreads are not retained in these software packages.
Colors:
- Avoid using a color palette of more than 255 colors. Delete any unused colors.
- Define all colors as CMYK builds unless the color will print as a spot color on press.
- Spot colors must not have any alternate color spaces other than CMYK.
- Do not save TIFF or EPS files with embedded color management profiles.
- Do not enable your page layout application´s color management tools, as these settings may be lost once your files leave your production environment.
- RGB, LAB, and ICC based colors must be converted to CMYK for print.
Design Tips- Although design and layout programs support many ways to create a document, some things should be avoided as they can cause problems in some plate making systems.
- InDesign “Fat” Type – Often when type is wrapped around an image, or if it just flows near it, the type can appear fattened or bold when the PDF is created. This is the result of transparency flattening, layering, and how the PostScript file is written. When InDesign writes the PostScript file, it must flatten all elements on the page into one layer. In doing this it can rasterize type that intersects an image even though this might not be apparent (it may intersect the part of the image that is not visible because it is outside of the picture box mask). The simple way to prevent this is to make sure that the type is "above" the image. To do this you can build your type on a layer above they image or select the type and choose "object – Arrange – Bring to Front". Another method is to "Outline" theaffected text or linework while in InDesign.
- InDesign or Illustrator Gradients and Vignettes – Vector gradients and vignettes made directly from InDesign or from Illustrator can be very complex to RIP and take excessive time to make plates. Rasterizing the gradient or vignette in Illustrator or Photoshop (at 300 dpi) and then placing it into your layout program as an image will greatly reduce
- Typesetting – All typesetting should be done in an application that will retain the vector properties of the text. Do not rasterize the text with pre-press editing software like Adobe Photoshop. The result of doing so will cause screened text on output to a postscript-printing device. Text should be saved as (vector) elements of the postscript file or in the line work layer of a raster file format such as Tiff-IT P1 or CT/LW.
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