PJTF stands for Portable Job Ticket Format. It is a meanwhile outdated file format that was used to define how pages should be processed for workflow systems. Just like PDF, PJTF was developed by Adobe. They sold the technology and software that uses this file format to various OEM-customers in the graphic arts market. PJTF complements PDF. While the PDF standard describes the content of pages, PJTF describes how those pages should be processed.
A PJTF file can define the various production variables for a job that consists of one or more PDF files. PJTF data can be stored in a separate file that contains links to the associated PDF files or the PJTF data can be stored within a PDF file. Agfa Apogee and Creo Prinergy are two workflow systems that use PJTF internally to define how pages should be processed within their system. Unfortunately both workflows seem to rely heavily on proprietary extensions to the PJTF command set and they are mutually incompatible. You cannot use Apogee PJTF files in a Prinergy workflow and vice versa.
A number of imposition applications like Kodak Preps, Heidelberg SignaStation and Dynagram DynaStrip use PJTF files to describe how pages should be imposed. The PJTF file describes the press sheet geometry and page positions. A link in the PJTF file points to a separate PDF file which contains pages that are the size of the press sheet and that contain all of the press marks: crop marks, color bars, text marks,…
There are a number of workflow systems on the market that can read such files. Kodak Prinergy can read SignaStation PJTF files. Agfa ApogeeX can read a wide variety of PJTF files.
PJTF is pretty limited in its ambitions. It only defines prepress related data and is not used during the creation of a job, nor after the creation of plates or film. Other file formats like CIP3 complement it to allow the exchange of data between prepress, press and post-press systems.
Nowadays all these functions have been united in the JDF standard. This file format allows the exchange of data between prepress applications, press management systems, postpress equipment as well as MIS software. It is the successor of PJTF and (in the longer run) CIP3. No further work is taking place on the PJTF file format.