02-06-2017, 04:02 PM
Gimp is definitely not the tool for this. What you save is not really a PDF (it won't scale), it's bitmaps images, one per page. Look at the file size before/after (a plain text PDF is about 20Kbytes/page, converted to bitmap it is several hundred kbytes per page).
A possible tool for this is LibreOffice writer. It loads PDFs (if they aren't locked or if you know the password). You can use the drawing tools to overlay rectangles over what you want to hide, and export the result as a true PDF (ie, no loss of quality).
A possible tool for this is LibreOffice writer. It loads PDFs (if they aren't locked or if you know the password). You can use the drawing tools to overlay rectangles over what you want to hide, and export the result as a true PDF (ie, no loss of quality).