overlay one pdf or ps file on top of another

Question

I have two pdf or postscript files (I can work with either one). What I want to do is merge each page on top of the other so that page1 of document A will be combined with

Answer 1

You can do this with pdf files using the command line tool pdftk using the stamp or background option.

e.g.

$ pdftk file1.pdf background file2.pdf output combinedfile.pdf

This will only work with a one-page background file. If you have multiple pages, you can use the multibackground command instead.

Answer 2

PDFbox for Java supports a Overlay class which allows to merge PDFs this way. See this answer: Watermarking with PDFBox

However, both PyPDF2 and PDFbox have been unreliable in my experience, but perhaps this is helpful for someone.

Answer 3

You could convert both pdfs into images and overlay one on top of the other layer like.

A suitable graphics library that you could use this would work.

Watermark suggestion above has great potential too as long as you don't run into issues in your language or graphics/pdf library of choice.