I am trying to use pdfjam to take a PDF file and output another, where each page results from vertically joining two pages of the original. However, for some reason, the output file is completely blank, even if it has the right number of pages.

What I am doing is just opening the terminal in the desired location, and typing:

pdfjam --nup 1x2 --suffix two-on-one --a4paper input_file.pdf -o output_file.pdf

I'm desperate to find out what is going on. Help, please!

Also, if you don't know what is happening but can suggest another method for achieving the same result, that would be great, as I desperately need this to work soon.

2 Answers 2


Try cpdf -impose-xy "1 2" in.pdf -o out.pdf.

This imposes by joining each pair of pages together vertically. If you want to then scale the result down to fit a page size, you can use:

cpdf -scale-to-fit a4portrait out.pdf -o out2.pdf

  • Thank you for your help! For some reason my laptop doesn't recognize the cpdf command. Do I need to install something? I would love to make your solution work, to have something to resort to when pdfjam fails, but I think I found out what was happening with pdfjam: for some reason it does not work on a vector-based PDF, it has to be a bitmap PDF. Mar 2 at 11:49
  • 1
    Sure. It's at community.coherentpdf.com Mar 2 at 15:40

Just in case it helps someone else, I wanted to point out that the reason why pdfjam was not working was that, for some reason that I don't understand yet, it fails when applied to a vector-based PDF. As soon as I exported my notes from my tablet in a bitmap PDF instead of a vector-based one, I had no problem applying the command indicated in my question to join the pages as I described.

  • Can you confirm whether or not the accepted answer worked for vector-based PDFs? If so you might consider editing your question (in lieu of this answer) with the information above (problem only occurs with vector-based PDFs etc.) Your call
    – Blindspots
    Mar 2 at 18:38

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