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3 Variants of PDF/X

PDF/X has three variants, PDF/X-1a, PDF/X-3, and PDF/X-4. In some cases, a specific variant has different versions. Each variant has an arena of use, depending on the kinds of files you work with and the workflow you require. All variants share the PDF/X advantage of consistently describing a "reliable PDF file for print." But as with any printing options, you lose some flexibility when you gain greater control.

The following Table 1 details each variant, including its use and compatibility:

PDF Variants

When deciding which PDF/X variant to use, in general:

  • Choose PDF/X-1a: when CMYK files are required; you're sending digital ads to be reproduced on a press characterized to a printing standard such as SWOP (Specifications for Web Offset Publications) or SNAP (Specifications for Non-heat Advertising Printing); or when you want to maintain absolute control over a file's content and color appearance.

  • Choose PDF/X-3: if your workflow requires transferring data in CIELab or RGB color spaces, with conversion to CMYK occurring later. Use PDF/X-3 for complete files that you will send to digital presses or other color-managed environments, or for some digital ads, where you expect the printer to optimize color reproduction for the specific printing environment.

  • Choose PDF/X-4: for printing artwork with live transparency and layers. Expected to be ratified as a standard in 2007, PDF/X-4 supports transparent artwork and effects, as well as layers. Print workflow systems based on the Adobe PDF Print Engine will be able to process PDF/X-4 jobs natively, without flattening artwork or converting the file to PostScript.