PDF Flavor - Which one is best for you ?

Answering that question, brings up many questions and bears some discussion of what are the differences. A higher version does not presume a "better" PDF and in some cases works against you.

What is the difference between versions PDF 1.2 to PDF 1.6 ?

Each version roughly parallels the release of a major version of Adobe Acrobat. The short overly simple answers:

• PDF 1.2 = Acrobat 3.0 - relatively obsolete now
• PDF 1.3 = Acrobat 4.0 - The first version of PDF which truly had all the needed features to support "press-ready" PDF's including color management, ICC profiles etc. It also added javascript, interactive and multimedia capabilities. This standard is probably the safest to send if you are unsure of the capabilities of the receiver of your file. PDF/X-3 and a number of commercial print work flows are based on PDF 1.3.
• PDF 1.4 = Acrobat 5.0 - Actually, introduced with Illustrator 9. The main difference to concern Scribus users is both transparency and alpha transparency capabilites. This makes a major difference in where a PDF with these features can be printed. It takes either the latest commercial RIPs or certain Level 3 PostScript printers to use these features properly. Moreover, not all Level 3 PostScript printers will handle transparency. The latest versions of Ghostscript support the advanced PDF 1.4 features Scribus can create when exporting PDF.The most distinguishing feature of PDF 1.4 for Scribus is the ability to export true transparency in PDF. Note: Often, the only way you will be able to print exactly the transparency features viewed on-screen is to export PDF 1.4 and print from Acrobat Reader 5.x or newer.
• PDF 1.5 = Acrobat 6.0 - Among the most interesting for Scribus users: many improvements for "press-ready" PDF, the capability to have true layering within the PDF, PDF-X "pre-flight" capability, more security and interactive features, like the ability to add comments which are separate from the original doc. Scribus can support many PDF 1.5 features in the 1.3.x development version. PDF 1.5 can also support more sophisticated compression options for images using JPEG 2000.
• PDF 1.6 = Acrobat 7.0 - Refinements of the 1.5 features and more extensive use of PKI and digital signing for document control as well as extended commenting for group collaboration. Where it concerns Scribus, nothing of importance, except the release of Adobe Reader 7.0 for Linux.

In deciding which version you choose for export, you need to consider the following:

• Where am I ultimately printing ? - If you are planning to have your files printed commercially, always try to ask the printer first.
• Does my document have transparency features ? - See above and ensure the rest of your equipment or workflow can support PDF 1.4.
• I am exporting PDF forms. How do I know end receivers of my file can use it ? - Do you know the version of Acro Reader your users will have ? The safest is to use PDF 1.3 or 1.4.
• Do I need layers ? - Only PDF 1.5 supports this and only in the 1.3.x version of Scribus. Be aware support for PDF 1.5 is not complete in most open source viewers. Ghostscript 8.5x does support some, but not all PDF 1.5 features.

What about other kinds of PDF I have read about, like PDF-X and PDF-A ?

PDF marked as any of the following: PDF/X-1:2001, X-1a:2001 and 2003; X-2:2003; X-3:2002 and 2003 are all different flavors of PDF-X, which is a way of creating a PDF with certain criteria for pre-press. Scribus supports the latest PDF-X-2:2003. Support for other versions of PDF/X is planned.

PDF-A is a draft ISO standard based on PDF 1.4 for long term storage of public documents in an open format.