materio-base-d7/sites/all/modules/contrib/admin/print/print_pdf/lib_handlers/print_pdf_wkhtmltopdf/INSTALL.txt

wkhtmltopdf support:
  wkhtmltopdf is a webkit-based tool that actually is a browser in order to
  generate the PDF.  Resource hungry: expect to need some 30Mb+ of RAM and
  some seconds of CPU power.  The static binaries may need additional
  libraries in your site, which may present problems in shared hosting
  environments.  The best, if you can run it.

  1. Download wkhtmltopdf from
  http://code.google.com/p/wkhtmltopdf/downloads/list. You can choose to
  download the source and compile it or simply download the static binary,
  which doesn't require you to compile anything. Note that the compiled
  version may require a running X server (static uses patched libs that can
  work without one).
  2. Place the wkhtmltopdf executable into one of the supported paths. 
  (usually sites/all/modules/print/lib).  You can also place a symbolic link
  to the executable.
  3. Check http://code.google.com/p/wkhtmltopdf/ for further information.