PDF Ground Controls Categories – Pages

The Ground Controls categories for Portable Document Format files are in the PDF Ground Controls area in FlightCheck preflight software by Markzware.

PAGES
This section of the Ground Control focuses on the layout of the file. Use these file layout Pages options to ensure that document’s page size is printable, based on the paper boundaries.

FlightCheck PDF Ground Control Categories Pages

Different Page Sizes:
One of the flexibilities of PDF creation is that you can combine unlike document sizes. (Ex. A book cover with spine and text pages) If you expect all the text to be the same size, use this feature to warn or indicate an error.

Different Page Orientation:
Horizontal and vertical pages can be combined within the same PDF file. To eliminate inconsistencies, check this feature.

Empty Pages:
Books may have blank pages with no folio information, but an Ad project would not. Set this based on your project needs.

Maximum Number of Pages:
A PDF document can have multiple pages. You may want to ensure that your document does not exceed a set number of pages (ex. a book). Type a number in the open field.

Maximum Number of Points in Path:
As you draw a vector path such as a circle, the path is divided into points that control the curve. Older versions of PostScript levels, had a limited range. Level 2 RIPS (Raster Image Processors–equipment used to process the plates for printing) have increased this number. Larger numbers placed within this field can add to the time required to process the file. Smaller number can make a circle appear choppy, or less rounded.

Embedded PostScript:
Fragments of Postscript can be incorporated or included in a PDF file. This can be incompatible in some versions of Adobe Reader (used for viewing only).

Actions:
Adobe Acrobat lets you add functions that set permissions, or play movies. PDF/X does not support actions within the specifications.

Javascripts:
A popular scripting language, Javascript is used with Adobe Acrobat to control objects by name and function within a PDF file. An example would be to click a button to reveal an image etc. These functions are not supported within PDF/X.

Forms:
Text Fields can be created by Adobe Acrobat that allow users to type information that adds data to a PDF file. These fields sit on a layer on top of the PDF and are normally not desired in a printing workflow.

Forms Using OPI:
OPI or Open Prepress Interface is a legacy method of using small low-resolution files to replace large high-resolution files during the layout stages. High-resolution files located at the RIP, would be substituted during processing. The OPI image could be a low-resolution image that repeats on several pages of a form. OPI is a method that saves processing time and disk space. It is no longer necessary, due to the cost of cheaper hard drives and faster processing speeds of newer computers.

Thumbnails:
Thumbnails are not part of a print focused workflow. They are used to  navigate a document on screen. Thumbnails direct users to pages within a PDF file, and can be eliminated in print workflows.

Overprint Mode:
Overprinting an image means that you set colors of an image to mix with colors in the image beneath it. If overprint mode is set to zero, process colors will not overprint to images that are deviceCMYK. (DeviceCMYK ties the color management to a specific output device) Best results allow the printer to set trapping values.

Layers:
Files built with Acrobat 6 or later can contain layers that help the user navigate the PDF. Layers can be used in technical drawings to separate electrical outlets or other images you might see in a architectural rendering. Layers are not suitable for most prepress workflows.
PAGES: BOXES
When designing for print, you start with an output or layout size–normally the size of the trimmed edge of the project. Other boxes are defined (but not viewable) to accommodate printing terms such as bleed, marks, etc. For PDF/X standards, each PDF must have structure defined in Boxes. Missing boxes can indicate that the elements may be floating within a page and not measured in a layout with margins and other marks.

Missing MediaBox:
The MediaBox is not found. MediaBox would be the layout trim size plus the medium (most cases paper) size. This is the largest box size- includes all Boxes.

Missing TrimBox:
The TrimBox is not found. The TrimBox measures from the trim marks inward, also known as live area.

Missing ArtBox:
The ArtBox is not found. The ArtBox is the one Box not important to the PDF/X specs. An ArtBox is a bounding box, or the square area or container that holds the art.

Missing CropBox:
The CropBox is not found. Adobe Acrobat tools can be used to crop a PDF file, in order to hide a partial view of a selected PDF.

Missing BleedBox:
The BleedBox is not found. This box extends past the bleed marks on the page to encompass the art trim size plus bleed size.

Missing TrimBox or ArtBox:
Either the TrimBox or ArtBox is not found. The ArtBox can be the same size as the Trimbox. PDF/X requires only the Trimbox to be present.

TrimBox and ArtBox are Present:
The TrimBox and Artbox are found. Only the TrimBox must be present. This option is similar to Missing TrimBox or ArtBox. It reports compliance.

CropBox Not Equal to MediaBox:
When cropping the view of the PDF you can change the size of the PDF. The MediaBox (the size of the media/paper/plate etc) should be the largest box to encompass all other boxes. The Crop should fit within the MediaBox.

Page Boxes not Nested:
Always create your document and save it before preflighting. A PDF file that contains the proper page boxes can be cropped in a way that internal page boxes can no longer be found. Coordinates described outside the media box (the largest box) will cause this error.
PAGES: ENCODING
Encoding is the method of modifying a file from one format to another. Compression may be used to make the file format smaller by keeping track of image colors in tables. Most format compressions can loose data, such as lossy, only a few are lossless.

ASCII Hexadecimal:
American Standard Code for Information Interchange (ASCII) is an encoding method that uses a numerical system.  Hexadecimal uses 16 base numbers (0-9 and letters A-F) to represent 256 bytes.

ASCII Base 85:
American Standard Code for Information Interchange (ASCII) is a modification method that represents four bytes of data with five ASCII characters.

LZW:
Abraham Lempel, Jacob Ziv, and Terry Welch created the LZW (Lempel- Ziv-Welch) compression instructions used to make file sizes smaller. Some RIPs have problems handling LZW encoded images.

Run Length:
A compression method used for images that are mainly solid black and white.

CCITT Facsimile:
The International Telegraph and Telephone Consultative Committee (CCITT) is a compression used for faxes that reduces monochrome images into low resolution scans.

DCT (JPEG):
Discrete Cosine Transform (DCT) is lossy data compression used in JPEG images.

Flate (ZIP):
Similar to Run Length, Flate/Zip is lossless compression that works best on repeating or single colors, such as screen shots.

JPEG2000:
(Joint Photographic Experts Group) JPEG files typically come from the internet or digital cameras and are usually lower resolution using lossy compression.

JBIG:
(Joint Bi-level Image Experts Group) is another method to compress monochromatic scans or faxes. This format offers better lossless compression than CCITT, a similar format.

Rendering:
This section defines elements that can manipulate color defined within PDF files.

Transfer Curves:
Transfer Functions can affect the final output of the pixels of an image. Transfer Functions are applied in Photoshop when saving as EPS, DCS1 and DCS2 file formats. A Transfer function can be used to correct a poorly calibrated device by compensating for dot gain on press. Using a transfer function may interfere with a printer’s normal color management procedure.

Halftone:
Similar to Transfer Curves, these are specified angles given for the CMYK components of a color image that can alter the actual pixel data in an image.

Halftone Type other than 1 or 5:
Halftones describe the screen frequency in angles for a specific device. Type 1 defines Frequency, Angle and SpotFunction (prevention of moiré patterns), where Type 5 identifies primary and spot colors. Reporting indicates if other types such as 2,3,4 ,6, etc. are included.
PAGES: DEFINED HALFTONE NAME

Halftone Phase:
This is a legacy problem of shifts within halftone and pattern cells found in older applications such as Corel Draw 7 Windows software.

Undercolor Removal Function:
UCR is the process of removing yellow, magenta, and cyan from dark shadows and midtone areas to solve an ink-sticking problem during printing. These colors are replaced with Black.

Black-Generation Function:
An RGB image can be converted to CMYK for printing. The black plate or Key plate is generated.

PAGES: ANNOTATION
Adobe Acrobat has commenting tools that add sticky notes, stamps, markup text, etc. Most comments/annotations are not desired for prepress workflows.

Annotation:
Defined as a note, an annotation is a stamp or a review method created in Acrobat. Notes reside on a layer on top of the PDF. You can also add traps and printer marks to this list.

Annotation in Printing Area:
Having notes outside of the printing area is acceptable and will not interfere with file processing. Notes in the live area will need to be removed, based on the PDF/X specs.

Annotation Set to Print:
Document Markups and Stamps can be printed from within the print dialog settings in Acrobat.

Audio:
WAV or AIFF files can be added to the PDF file with the Audio Comment Tool.

Text:
Text can be reviewed by using highlighting, strikethroughs, or underlining tools for commenting.

Note:
A sticky note allows the user to add text, provide a timestamp, author and special icon if desired.

File:
PDFs can include the original source file as an attachment.

Stamp:
Acrobat has several categories of stamps that can be placed on top of a PDF document.

Movie:
Movie files can be embedded or linked to an outside file.

PAGES: TrapNet

Printer’s Mark:
Printer’s marks can be added to a PDF file by either embedding or adding temporarily, and are often on a separate layer.

Custom for PDF 1.3:
Annotations can be customized, and should remain outside of the bleed or live area.

PAGES: ACROFORM
A flat PDF file can have a layer that includes buttons, fields or javascript form functions. PDF/X standards do not work with supplementary additions to a PDF that are included within the live area.

AcroForms:
Adobe Acrobat can be used to save a PDF with form fields and buttons. These forms are generally not suited for printing workflows.

Acrobat Forms in Printing Area:
Forms fields should not be located in the live area of the PDF.