Let's say I have stamp.pdf or stamp.html and original.pdf.
stamp.pdf (stamp.html) contains a stamp and I want to place stamp.pdf over original.pdf in a certain position and generate a new pdf - original_stamped.pdf.
I would like to insert stamp.pdf as a pdf (vector graphic) or as html, but not converting to raster image and then insert into original_stamped.pdf.
I am talking about stamping or watermarking (over the page), but not just adding an additional page to pdf.