Preflight PDF files

PDF quality control or preflight is used to check PDF documents to make sure they are suitable for use in print, in an archive or whatever other purpose they have. callas created its preflight technology to perform such quality control manually and or fully automated. As a testament to the quality and reliability of the callas preflight engine, it was licensed by Adobe and is used in the Acrobat Preflight plug-in. Read on to learn how to preflight your PDF documents in various ways.

It all starts with a profile

The cornerstone of any quality control done with a callas product is a so-called preflight profile. A profile is a collection of the checks you want to do on a PDF document and (optionally) the problems you want to fix while preflighting. In order to be able to preflight your PDF documents, you will either have to choose a predefined preflight profile (one included in the product by callas) or you will need to make your own.

The predefined profiles provided by callas fall roughly in the following categories:

  • Profiles following PDF standards such as PDF/X, PDF/A, PDF/VT and more
  • Profiles implementing PDF specifications from industry associations such as the Ghent Workgroup and PDF/X-Ready
  • Other example and demo profiles

Figure 1: the pdfToolbox Profile window showing ISO standard profiles

Manual preflight

When you receive a PDF document, you can inspect it manually using pdfToolbox Desktop or pdfaPilot Desktop. Both products operate either as a plug-in inside of Adobe Acrobat or as a standalone application. Preflighting your documents is as easy as opening the PDF file you want to check, selecting the correct preflight profile in the “Profiles” window and hitting the “Analyze” or “Analyze and fix” button.

Figure 2: preflight results for a PDF/X-1a profile

When performing a manual preflight, the “Result” window pops up and displays a list of informational items, warnings and errors.

Using watched folders to preflight

In many workflows it is more efficient to organize automated preflight; instead of opening each PDF individually, a hot folder or watched folder is setup. Any PDF document dropped in this folder is automatically picked up and preflighted. The results are moved to predefined folders.

Figure 3: a watched folder setup in pdfToolbox Server to create PDF/X-4 files

pdfToolbox Server and pdfaPilot Server implement this type of automated workflow. Each created job defines an input folder (the watched folder where PDF files are picked up from) and output folders for files without errors, files with errors, files with warnings and so on. The preflight profile selected in the job defines which checks and fixes are going to be executed on processed files.

Integrated preflight

Often the most efficient way to preflight PDF files is integrated into a larger solution such as a delivery portal or web-to-print solution. callas provides both a command-line solution and a real SDK to support these scenarios.

Command-line integration

pdfToolbox CLI and pdfaPilot CLI are command-line applications; they can be started from a terminal or command window, but are typically launched from the application or script they are integrated with. These versions of the applications support all of the preflight capabilities and can automatically generate detailed reports (in PDF or XML) for further integration.

Using the SDK

pdfToolbox SDK and pdfaPilot SDK are solutions providing integration on a library level. The SDK contains the necessary libraries, headers, documentation and samples to integrate preflight closely in a C, C++, Java or .Net application. Integrating preflight using the SDK requires development resources but does allow for the closest integration in the end.


You can read much more about all of the products mentioned in the product pages on the web site. Or simply contact us for a personalized demo or to ask more in-depth questions.