Papermerge supports PDF, TIFF, JPEG and PNG file formats.
PDF format is called native because Papermerge interals operate as if all documents are PDF.
TIFF, JPEG or PNG on the other hand are not native (non-native) formats.
The import of native format yields one version document - the PDF itself i.e. orignal version.
The import of any non-native formats yields two versions document:
- version 1 with non-native file i.e. original file
- version 2 with PDF file into which non-native format was converted
At its core Papermerge code is written to work with PDF files only. All other files (non-natives) are converted, on import, into PDF format.