Creating a PDF/X-3 document with CapyPDF

The original motivation for creating CapyPDF was understanding how fully color managed and print-ready PDF files are actually put together. A reasonable measure of this would be being able to generate fully spec conforming PDF/X-3 files. Most of the building blocks were already there so this was mostly a question of exposing all that in Python and adding the missing bits.

I have now done this and it seems to work. The script itself can be found in CapyPDF's Git repo and the generated PDF document can be downloaded using this link. It looks like this in Acrobat Pro.

It is not graphically the most flashy, but it requires quite a lot of functionality:

• The document is A4 size but it is defined on a larger canvas. After printing it needs to be cut into the final shape. This is needed as the document has a bleed.
• To obtain this the PDF has a bleed box (the blue box) as well as a trim box (the green box). These are not painted in the document itself, Acrobat Pro just displays them for visualisation purposes.
• All colors in graphical operations are specified in CMYK.
• The image is a color managed CMYK TIFF. It has an embedded ICC profile that is different from the one used in final printing. This is due to laziness as I had this image laying around already. You don't want to do this in a real print job.
• The heading has both a stroke and a fill
• The printer marks are just something I threw on the page at random.

Here is a screenshot of the document passing PDF-X/3 validation in Acrobat Pro.